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Contents
- The climate of Aarau
- The best time to visit Aarau
- The worst time to visit Aarau
- Spring weather in Aarau
- Summer weather in Aarau
- Autumn weather in Aarau
- Winter weather in Aarau
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Climate and monthly weather forecast
The climate of Aarau
Aarau, nestled in the heart of Switzerland, is characterized by a Marine West Coast climate, warm summer, and officially classified by the Köppen climate classification as Cfb. This classification is predominantly due to the uniquely temperate weather conditions typically observed in this region throughout the year.
Examining the temperature trends over the twelve months, the average highs range from 2.9°C (37.2°F) in the winter month of January to 23.3°C (73.9°F) in the summer months of July and August. On the other hand, the average low swings between a chilling -3.3°C (26.1°F) in January to a relatively comfortable 11.8°C (53.2°F) in July and August. This diverse temperature spread reflects the region's distinctive blend of weather nuances across different seasons.
Of great significance in Aarau’s climate is its balanced distribution of rainfall. Throughout the year, the rain gauge records quantities varying from 45mm (1.77") in September to 106mm (4.17") in May. May also marks the month with the highest number of rainy days, counting up to 22.4 days. December sees the highest snowfall, with 143mm (5.63") recorded, while June, July, August, and September remain virtually snow-free.
Furthermore, the daylight varies from a minimum of 8.6 hours in December to a maximum of 15.9 hours in June, demonstrating the typical contrast between shorter winter days and extended summer daylight. The uncertainty and fluctuation in this weather pattern, coupled with the intriguing natural beauty of Switzerland, unarguably contribute to the peculiar charm of Aarau.
Examining the temperature trends over the twelve months, the average highs range from 2.9°C (37.2°F) in the winter month of January to 23.3°C (73.9°F) in the summer months of July and August. On the other hand, the average low swings between a chilling -3.3°C (26.1°F) in January to a relatively comfortable 11.8°C (53.2°F) in July and August. This diverse temperature spread reflects the region's distinctive blend of weather nuances across different seasons.
Of great significance in Aarau’s climate is its balanced distribution of rainfall. Throughout the year, the rain gauge records quantities varying from 45mm (1.77") in September to 106mm (4.17") in May. May also marks the month with the highest number of rainy days, counting up to 22.4 days. December sees the highest snowfall, with 143mm (5.63") recorded, while June, July, August, and September remain virtually snow-free.
Furthermore, the daylight varies from a minimum of 8.6 hours in December to a maximum of 15.9 hours in June, demonstrating the typical contrast between shorter winter days and extended summer daylight. The uncertainty and fluctuation in this weather pattern, coupled with the intriguing natural beauty of Switzerland, unarguably contribute to the peculiar charm of Aarau.
The best time to visit Aarau
The optimal time for a visit to Aarau falls in the summer months of June to August, with temperatures reaching a pleasant 21.2°C (70.2°F) to 23.3°C (73.9°F) on average. This period also presents an opportunity to bask in the generous daylight, reaching a high of 15.9 hours in June. The rainfall in summer averages around 100mm (3.94") to 105mm (4.13"), which contributes to the overall refreshing ambiance of the region.
The worst time to visit Aarau
Taking into account the various climatic conditions, it appears that the winter months of December through February may not be the best time for a visit. During this period, temperatures frequently drop below freezing, and the amount of daylight is at its yearly minimum, peaking only at 9 hours in February. Besides, substantial snowfall occurs during these months, which may hinder mobility for certain visitors.
Spring weather in Aarau
In Aarau, spring spans from March to May, bringing about a gentle rise in temperature from 9°C (48.2°F) in March to 17.3°C (63.1°F) in May. Notably, May also has the highest rainfall at 106mm (4.17") with an average of 22.4 rainy days. Daylight steadily increases from 11.9 hours in March to a generous 15.1 hours in May, while the sunshine hours peak at 9.1 in May, contributing to the overall pleasant spring ambiance.
Summer weather in Aarau
Summer in Aarau, from June to August, is marked by warm temperatures averaging between 21.2°C (70.2°F) and 23.3°C (73.9°F). Rainfall is moderate, ranging from 100mm (3.94") in July to 105mm (4.13") in June. The area becomes devoid of snowfall, and daylight reaches 15.9 hours in June, progressively reducing to 14.2 hours in August. Sunshine hours also peak during this season, ranging from 10.3 hours in July to 10.4 hours in August.
Autumn weather in Aarau
Autumn in Aarau sets in from September to November. The season is signified by reducing temperatures from 18.8°C (65.8°F) in September to 8.3°C (46.9°F) by November. Daylight hours also reduce from 12.6 in September to 9.4 hours in November. Precipitation is moderate, with rainfall ranging from 45mm (1.77") in September to 60mm (2.36") in November, marking an overall cooler and wetter season.
Winter weather in Aarau
Winter in Aarau, beginning in December and ending in February, demonstrates a palpable drop in temperatures with averages falling between -3.3°C (26.1°F) and 3.8°C (38.8°F). Snowfall is abundant, peaking at 143mm (5.63") in December. The daylight lasts for about 9 hours, and the sunshine hours diminish to their lowest at 5 hours. Consequently, these conditions paint a compelling picture of a typical Swiss winter.
Weather in January
The beginning of the year in Aarau, Switzerland, sees chilly temperatures and snowfall. January experiences the coldest weather with minimum temperatures dipping to -3.3°C (26.1°F) amid the winter season. With shorter daylight hours, locals often enjoy cozy indoors while slight window frost gives a picturesque feel to the Swiss cityscape. Weather in January »
Weather in February
Though February sustains the winter's chill, Aarau experiences a gradual creep in temperature from this month. Witnessing maximum snowfall of 153mm (6.02"), Aarau adorns a fresh white cloak. Winters continue to assert their dominance, however, February introduces a slightly longer daylight offering delightful afternoons. Weather in February »
Weather in March
Spring knocks the doors of Aarau in March, bringing with it warmer days and blooming landscapes. The shift from winter chill to spring warmth becomes pretty evident during this time. The receding snowfall clears the way for blossoming flora, revealing the grassy terrains underneath the pristine white cover. Weather in March »
Weather in April
April, in Aarau, is marked by spring in full bloom accompanied by extended daylight hours. It is a pleasant shift from the chilling weather of the first quarter of the year. With snow almost entirely disappeared, outdoor activities gain momentum. Weather in April »
Weather in May
May brings the scent of blossoms and the melody of birdsong to Aarau. With the increase in sunshine hours, day activities serve as excellent recreations. The first month of summer, May displays an impressive temperature high of 17.3°C (63.1°F). Weather in May »
Weather in June
June unfurls the season of summer in all its glory in Aarau, making it a favored month for tourists. The weather is warmer, and the city looks breathtaking under the sharp summer sunlight. Outdoor enthusiasts can make the most of this weather due to longer daylight hours. Weather in June »
Weather in July
July becomes synonymous with warm sunlit days and cool summer nights in Aarau. The pleasant weather makes it a perfect canvas for travelers to paint their summer trips. As the weather heats up to 23.3°C (73.9°F), people engage in various outdoor activities. Weather in July »
Weather in August
Aarau, in August, basks in the charm of late summer. With temperatures aligning to 23.3°C (73.9°F) yet again, warmth wraps the city comfortably. August comes with abundant sunshine, inviting locals and visitors to enjoy outdoor recreational pursuits. Weather in August »
Weather in September
September marks the arrival of autumn in Aarau, signaling a transition from warm to mild weather. The summer's heat begins to fade, making way for comfortable temperature and occasional showers. The transformation from lush green to hues of orange and yellow unfolds a unique spectacle. Weather in September »
Weather in October
October paints Aarau in vibrant hues of fall and progressively cooler temperatures. It brings a decreased daylight duration, hinting towards the arrival of winter. The weather is pleasingly cool, prompting locals and tourists to revel in outdoor activities. Weather in October »
Weather in November
Aarau in November presents the departure of the fall and the arrival of early winter. The city wraps itself in a full-fledged winter coat with an average temperature diving down to 8.3°C (46.9°F). The days grow shorter and colder while nights witness an increase in chill. Weather in November »
Weather in December
Finally, December arrives in Aarau marking the zenith of the cold winter season. Featuring the year's heaviest rainfall of 81mm (3.19"), it gears up for the festive spirit. With daylight receding to its shortest duration, afternoons get clouded by early dusk. Weather in December »
Updated: Aug 22, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the coldest time of year?
January tends to be the coldest month, with temperatures averaging a daily high of 2.9°C (37.2°F) and a low of -3.3°C (26.1°F).
What is the most humid month?
January is the most humid month, with an average relative humidity of 88%.
How many days does it rain?
In Aarau, during the entire year, the rain falls for 190.8 days and collects up to 880mm (34.65") of precipitation.
When does it snow?
January through May, October through December are months with snowfall.
How many days does it snow?
In Aarau, during the entire year, snow falls for 39.9 days and aggregates up to 652mm (25.67") of snow.
What are the months with the lowest UV index?
The months with the lowest UV index are January, February, October through December, with an average maximum UV index of 2.
What is the snowiest month?
The month with the most snowfall is February, when snow falls for 9.7 days and typically aggregates up to 153mm (6.02") of snow.
What is the least humid month?
The months with the lowest humidity are April and July, with an average relative humidity of 78%.
What is the wettest month?
The month with the most rainfall is May, when the rain falls for 22.4 days and typically aggregates up to 106mm (4.17") of precipitation.
When it does not snow?
June through September are months without snowfall.
When are the longest days?
The month with the longest days is June, with an average of 15h and 54min of daylight.
What is the month with the highest UV index?
The months with the highest UV index are June and July, with an average maximum UV index of 5.
What is the warmest month in Aarau?
July and August are characterised by peak temperatures, with an average high of 23.3°C (73.9°F).
What month has the most sunshine?
The month with the most sunshine is August, with an average of 10.4h of sunshine.
What is the driest month?
September is the month with the least rainfall. Rain falls for 14.5 days and accumulates 45mm (1.77") of precipitation.
When is Daylight Saving Time (DST)?
On Sunday, 27. October 2024, at 03:00, Daylight Saving Time ends, and the time zone changes from CEST to CET. The next Daylight Saving Time starts on Sunday, 30. March 2025, at 02:00, and the time zone reverts from CET to CEST.
What is the month with the shortest days in Aarau?
December has the shortest days of the year, with an average of 8h and 30min of daylight.
What is the month with the least sunshine?
December has the least sunshine of the year, with an average of 5h of sunshine.
Average temperature
Aarau, Switzerland
The warmest months (with the highest average high temperature) are July and August (23.3°C).
The month with the lowest average high temperature is January (2.9°C).
The months with the highest average low temperature are July and August (11.8°C).
The coldest month (with the lowest average low temperature) is February (-3.4°C).
Average pressure
Aarau, Switzerland
- Average pressure in January:
1019.5mbar - Average pressure in February:
1017.8mbar - Average pressure in March:
1017.1mbar - Average pressure in April:
1015.6mbar - Average pressure in May:
1016.3mbar - Average pressure in June:
1016.6mbar
- Average pressure in July:
1017.1mbar - Average pressure in August:
1017.7mbar - Average pressure in September:
1018.6mbar - Average pressure in October:
1018.5mbar - Average pressure in November:
1015.8mbar - Average pressure in December:
1020.9mbar
The month with the highest atmospheric pressure is December (1020.9mbar).
The month with the lowest atmospheric pressure is April (1015.6mbar).
Average wind speed
Aarau, Switzerland
- Average wind speed in January:
8.3km/h - Average wind speed in February:
8.6km/h - Average wind speed in March:
8.8km/h - Average wind speed in April:
7.5km/h - Average wind speed in May:
7.6km/h - Average wind speed in June:
7km/h
- Average wind speed in July:
6.7km/h - Average wind speed in August:
5.9km/h - Average wind speed in September:
6.4km/h - Average wind speed in October:
6.5km/h - Average wind speed in November:
7.1km/h - Average wind speed in December:
8.5km/h
The windiest month (with the highest average wind speed) is March (8.8km/h).
The calmest month (with the lowest average wind speed) is August (5.9km/h).
Average humidity
Aarau, Switzerland
The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are April and July (78%).
Average rainfall
Aarau, Switzerland
- Average rainfall in January:
59mm - Average rainfall in February:
56mm - Average rainfall in March:
56mm - Average rainfall in April:
56mm - Average rainfall in May:
106mm - Average rainfall in June:
105mm
The wettest month (with the highest rainfall) is May (106mm).
The driest month (with the least rainfall) is September (45mm).
Average rainfall days
Aarau, Switzerland
- Average rainfall days in January:
12.8 days - Average rainfall days in February:
10.6 days - Average rainfall days in March:
14.3 days - Average rainfall days in April:
16.3 days - Average rainfall days in May:
22.4 days - Average rainfall days in June:
20.3 days
- Average rainfall days in July:
20.7 days - Average rainfall days in August:
18.3 days - Average rainfall days in September:
14.5 days - Average rainfall days in October:
13.2 days - Average rainfall days in November:
12.2 days - Average rainfall days in December:
15.2 days
The month with the highest number of rainy days is May (22.4 days).
The month with the least rainy days is February (10.6 days).
Average snowfall
Aarau, Switzerland
The month with the highest snowfall is February (153mm).
The months with the least snowfall are June, July, August and September (0mm).
Average snowfall days
Aarau, Switzerland
- Average snowfall days in January:
9.5 days - Average snowfall days in February:
9.7 days - Average snowfall days in March:
6.2 days - Average snowfall days in April:
1.3 days - Average snowfall days in May:
0.4 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.4 days - Average snowfall days in November:
4.5 days - Average snowfall days in December:
7.9 days
The month with the highest number of snowfall days is February (9.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Aarau, Switzerland
- Average daylight in January:
9h and 0min - Average daylight in February:
10h and 2min - Average daylight in March:
11h and 5min - Average daylight in April:
13h and 4min - Average daylight in May:
15h and 1min - Average daylight in June:
15h and 5min
- Average daylight in July:
15h and 3min - Average daylight in August:
14h and 1min - Average daylight in September:
12h and 4min - Average daylight in October:
10h and 5min - Average daylight in November:
9h and 2min - Average daylight in December:
8h and 3min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in January:
5h and 1min - Average sunshine in February:
5h and 2min - Average sunshine in March:
7h and 1min - Average sunshine in April:
9h and 1min - Average sunshine in May:
9h and 1min - Average sunshine in June:
9h and 5min
- Average sunshine in July:
10h and 2min - Average sunshine in August:
10h and 2min - Average sunshine in September:
8h and 5min - Average sunshine in October:
6h and 2min - Average sunshine in November:
5h and 4min - Average sunshine in December:
5h and 0min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).
Average sunshine days
Aarau, Switzerland
- Average sunshine days in January:
11.8 days - Average sunshine days in February:
11.4 days - Average sunshine days in March:
12.4 days - Average sunshine days in April:
12.2 days - Average sunshine days in May:
6.6 days - Average sunshine days in June:
6.8 days
- Average sunshine days in July:
7.6 days - Average sunshine days in August:
9.6 days - Average sunshine days in September:
12.2 days - Average sunshine days in October:
15 days - Average sunshine days in November:
13.4 days - Average sunshine days in December:
12.4 days
The month with the most sunshine days is October (15 days).
The month with the least sunshine days is May (6.6 days).
Average UV index
Aarau, Switzerland
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover
Aarau, Switzerland
The month with the most cloud cover is January (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility
Aarau, Switzerland
The months with the highest visibility are March, April, July and August (9km).
The months with the lowest visibility are January, February, May, June, September, October, November and December (8km).
