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Contents
- The climate of San Diego
- The best time to visit San Diego
- The worst time to visit San Diego
- Spring weather in San Diego
- Summer weather in San Diego
- Autumn weather in San Diego
- Winter weather in San Diego
- 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 daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
The climate of San Diego
The weather pattern of San Diego, Costa Rica can be classified as Am according to the Köppen climate classification. This indicates a tropical monsoon climate, typical for regions located near the equator. A constant fluctuation between different weathers conditions, from hot to rainy, further influences this geographical setting.
Throughout the year, temperatures in San Diego exhibit little fluctuation. The area experiences an annual average high temperature ranging from 22.2°C (72°F) to 25.3°C (77.5°F) and a low temperature variance from 13.7°C (56.7°F) up to 16.9°C (62.4°F). Relative humidity levels change moderately, oscillating between 76% and 90%. Rainfall presents significant seasonal variation. It is minimal in February, with 33mm (1.3"), jumping to 444mm (17.48") at its peak in October. Analogously, the number of rainfall days changes from 14.9 in February to a high of 30.5 in October.
With regards to sunlight, the city benefits from around 11.6 to 12.7 hours of daylight per month. The actual sun exposure is slightly less, with sunshine hours varying from 6.5 to 9.1 hours. San Diego also maintains an average monthly UV index of 5. However, the amount of cloud cover increases during the monsoon season, resulting in reduced visibility, from 9km (5.6mi) on average to a minimum of 6km (3.7mi) in September and October.
The city experiences steady air pressure throughout the year, hovering around 1011.3mb to 1012.4mb. Wind conditions vary slightly; from 3.7km/h (2.3mph) to 8.6km/h (5.3mph). Gusts of wind are also a regular phenomenon, ranging from 5.8km/h (3.6mph) to 13.4km/h (8.3mph).
Throughout the year, temperatures in San Diego exhibit little fluctuation. The area experiences an annual average high temperature ranging from 22.2°C (72°F) to 25.3°C (77.5°F) and a low temperature variance from 13.7°C (56.7°F) up to 16.9°C (62.4°F). Relative humidity levels change moderately, oscillating between 76% and 90%. Rainfall presents significant seasonal variation. It is minimal in February, with 33mm (1.3"), jumping to 444mm (17.48") at its peak in October. Analogously, the number of rainfall days changes from 14.9 in February to a high of 30.5 in October.
With regards to sunlight, the city benefits from around 11.6 to 12.7 hours of daylight per month. The actual sun exposure is slightly less, with sunshine hours varying from 6.5 to 9.1 hours. San Diego also maintains an average monthly UV index of 5. However, the amount of cloud cover increases during the monsoon season, resulting in reduced visibility, from 9km (5.6mi) on average to a minimum of 6km (3.7mi) in September and October.
The city experiences steady air pressure throughout the year, hovering around 1011.3mb to 1012.4mb. Wind conditions vary slightly; from 3.7km/h (2.3mph) to 8.6km/h (5.3mph). Gusts of wind are also a regular phenomenon, ranging from 5.8km/h (3.6mph) to 13.4km/h (8.3mph).
The best time to visit San Diego
With the dry season running from December to April, these months emerge as the preferred period to visit San Diego. During this interval, the temperature stays between 22.2°C (72°F) and 24.3°C (75.7°F) with reduced humidity levels, a comparative rarity in this tropical region. Rainfall decreases significantly, especially in February where a mere 33mm (1.3") of rain is expected. Additionally, the average sunshine duration ranges from 8 to 9.1 hours, making outdoor explorations more appealing and comfortable.
The worst time to visit San Diego
The monsoon season from May to November makes this period less convenient for visits. During these months, rainfall intensifies substantially, reaching a marked high of 444mm (17.48") in October. This interval also sees an upsurge in rainy days, with the number escalating to almost the entire month in October. Visibility diminishes due to the increased cloud cover, dropping to 6km (3.7mi) in September and October. The humidity levels also reach their zenith, which, coupled with average high temperatures of between 22.9°C (73.2°F) and 23.7°C (74.7°F), contributes to an uncomfortable, muggy atmosphere.
Spring weather in San Diego
Spring in San Diego, stretching from March to May, tends to be warm and increasingly wet. The temperature moves from 24.9°C (76.8°F) to 23.7°C (74.7°F), accompanied by an upward trend in rainfall and humidity. Rainfall rises from 39mm (1.54") in March to 367mm (14.45") in May, and humidity levels increase from 77% to 86%.
Summer weather in San Diego
Summer months in San Diego, from June to August, are characterized by high humidity and rainfall. The average high temperature ranges from 23°C (73.4°F) to 23.7°C (74.7°F) with downpours reaching between 352mm (13.86") and 307mm (12.09"). Humidity escalates up to 89%, lending the air a distinctly sticky quality.
Autumn weather in San Diego
Autumn in San Diego, Costa Rica, lasts from September to November, and is characterized by the heaviest rainfall of the year. Temperatures stay relatively constant, fluctuating between 22.4°C (72.3°F) to 22.9°C (73.2°F). Rainfall reaches a peak of 444mm (17.48") in October, with the number of rainy days topping at 30.5. Humidity stays high at around 88% to 90%.
Winter weather in San Diego
Spanning from December to February, winter in San Diego experiences slightly cooler conditions. The high temperature revolves around 22.4°C (72.3°F) to 23.5°C (74.3°F), while lows dip to between 13.7°C (56.7°F) to 14.3°C (57.7°F). Consistent with most tropical climates, the driest part of the year falls within these months, with rainfall decreasing to 45mm (1.77") in December and reaching a yearly low of 33mm (1.3") in February. Conversely, the number of sunshine hours increases, with an average of 8 to 9.1 hours of direct sunlight.
Weather in January
San Diego, Costa Rica, welcomes the new year with a mostly overcast sky, marked by a cloud presence of 34%. Relative humidity peaks at 79%, as the air gets a bit crisp. Despite this, the month still graciously allows sunshine for up to 8.8h a day. Weather in January »
Weather in February
February’s weather in San Diego sees a slight increase in sunshine hours, rising to 9.1h, contributing to clearer days. Nonetheless, the climate remains similar to the previous month, with teeming life thriving under the humid conditions. Weather in February »
Weather in March
March ushers in a period of notable transformation in San Diego's weather dynamics. Upon comparison with February, rainfall increases to 39mm (1.54"), ushering in the onset of the wetter season. The daylight hours start to extend, and the UV index remains constant. Weather in March »
Weather in April
April witnesses San Diego transition fully into its rainy season, as rainfall surges abundantly from the preceding month, measuring a significant increase to 103mm (4.06"). The increasing precipitation becomes a distinctive feature of the weather, creating fresh, verdant surroundings. Weather in April »
Weather in May
San Diego embraces the peak of its rainy season in May. The city receives a record high rainfall of 367mm (14.45"), distinguishing May as the wettest month of the year. Naturally, this month offers a different charm with its lush, green landscapes, refreshed by the showers. Weather in May »
Weather in June
June in San Diego continues the wet spell from May, maintaining a high level of rainfall while also observing the highest humidity level at 89%. The weather conditions invite a unique flora and fauna showcasing a different facet of the city’s natural beauty. Weather in June »
Weather in July
Although July follows the highly humid months of May and June, San Diego sees a slight decrease in rainfall to 271mm (10.67"). It provides a comfortable environment, boasting a continuous cover of greenery reenergized from prior showers. Weather in July »
Weather in August
As the calendar flips to August, San Diego witnesses a gradual slackening of the showers compared to July, with rainfall measuring 307mm (12.09"). The city's weather retains its consistency, with the UV index, daylight hours, and temperature remaining relatively stable. Weather in August »
Weather in September
September sees an escalation in rainfall back to 320mm (12.6"), as the month stands shoulder to shoulder with the showers that define San Diego's weather. Amid the predictable rain and high humidity, daylight hours start decreasing, preparing the way for the forthcoming cooler period. Weather in September »
Weather in October
October takes the crown for the city's highest rainfall, reaching an annual peak of 444mm (17.48"). The temperatures maintain a balance, neither soaring too high nor falling too low. As San Diego inches closer to the end of the wet season, the weather starts hinting at the forthcoming change, though the covered skies, and regular showers continue to be a constant companion. With an average high-temperature of 22.2°C (72°F) and an average low-temperature of 16.3°C (61.3°F), October is the coldest month. Weather in October »
Weather in November
Weather in San Diego witnesses a significant turning point in November, with rainfall plummeting drastically to 174mm (6.85") from the lofty heights of October. This drop signals the commencement of the dry season marking a clear shift in the climate from the preceding wet months. Weather in November »
Weather in December
San Diego closes the year with a final drop in rainfall levels to 79mm (3.11"), as December cements its place in the dry season. Despite this, the city remains fresh and verdant, bearing the fruits of the plentiful showers of the bygone months. Weather in December »
Updated: Jan 26, 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
How much does it rain in San Diego?
Throughout the year, in San Diego, Costa Rica, there are 305 rainfall days, and 2534mm (99.76") of precipitation is accumulated.
When is the highest UV index in San Diego?
The months with the highest UV index in San Diego are January through December, with an average maximum UV index of 5.
When is the lowest UV index in San Diego?
January through December, with an average maximum UV index of 5, are months with the lowest UV index.
What is the least humid month in San Diego?
February is the least humid month in San Diego, with an average relative humidity of 76%.
What is the driest month in San Diego?
The month with the least rainfall in San Diego is February, when the rain falls for 14.9 days and typically collects 33mm (1.3") of precipitation.
What month has the most sunshine in San Diego?
The month with the most sunshine in San Diego is February, with an average of 9.1h of sunshine.
What part of the year is the hottest in San Diego?
April, with its high-temperature average of 25.3°C (77.5°F) and a low-temperature average of 15.8°C (60.4°F), is the warmest month.
When are the longest days in San Diego?
June has the longest days of the year, with an average of 12h and 42min of daylight.
What is the coldest month in San Diego?
October is the month when San Diego sees the average lowest temperatures, with a high of 22.2°C (72°F) and a low of 16.3°C (61.3°F).
What is the most humid month in San Diego?
October is the most humid month, with an average relative humidity of 90%.
What is the rainiest month in San Diego?
The month with the most rainfall in San Diego is October, when the rain falls for 30.5 days and typically aggregates up to 444mm (17.48") of precipitation.
What is the month with the least sunshine in San Diego?
October has the least sunshine of the year, with an average of 6.5h of sunshine.
What is the month with the shortest days in San Diego?
With an average of 11h and 36min of daylight, December has the shortest days of the year in San Diego, Costa Rica.
Is there Daylight Saving Time (DST) in San Diego?
San Diego does not observe Daylight Saving Time (DST). CST timezone is used throughout the entire year.
Average temperature
San Diego, Costa Rica
The warmest month (with the highest average high temperature) is April (25.3°C).
The month with the lowest average high temperature is October (22.2°C).
The month with the highest average low temperature is May (16.9°C).
The coldest month (with the lowest average low temperature) is January (13.7°C).
Average pressure
San Diego, Costa Rica
- Average pressure in January:
1012.4mbar - Average pressure in February:
1012.1mbar - Average pressure in March:
1012.2mbar - Average pressure in April:
1011.6mbar - Average pressure in May:
1011.3mbar - Average pressure in June:
1011.3mbar
- Average pressure in July:
1011.6mbar - Average pressure in August:
1011.4mbar - Average pressure in September:
1011.2mbar - Average pressure in October:
1010.9mbar - Average pressure in November:
1011.1mbar - Average pressure in December:
1011.8mbar
The month with the highest atmospheric pressure is January (1012.4mbar).
The month with the lowest atmospheric pressure is October (1010.9mbar).
Average wind speed
San Diego, Costa Rica
- Average wind speed in January:
8.4km/h - Average wind speed in February:
8.6km/h - Average wind speed in March:
7.9km/h - Average wind speed in April:
5.9km/h - Average wind speed in May:
4.4km/h - Average wind speed in June:
4.3km/h
- Average wind speed in July:
5.7km/h - Average wind speed in August:
4.7km/h - Average wind speed in September:
3.7km/h - Average wind speed in October:
3.8km/h - Average wind speed in November:
5.3km/h - Average wind speed in December:
7.2km/h
The windiest month (with the highest average wind speed) is February (8.6km/h).
The calmest month (with the lowest average wind speed) is September (3.7km/h).
Average humidity
San Diego, Costa Rica
The month with the highest relative humidity is October (90%).
The month with the lowest relative humidity is February (76%).
Average rainfall
San Diego, Costa Rica
- Average rainfall in January:
45mm - Average rainfall in February:
33mm - Average rainfall in March:
39mm - Average rainfall in April:
103mm - Average rainfall in May:
367mm - Average rainfall in June:
352mm
- Average rainfall in July:
271mm - Average rainfall in August:
307mm - Average rainfall in September:
320mm - Average rainfall in October:
444mm - Average rainfall in November:
174mm - Average rainfall in December:
79mm
The wettest month (with the highest rainfall) is October (444mm).
The driest month (with the least rainfall) is February (33mm).
Average rainfall days
San Diego, Costa Rica
- Average rainfall days in January:
17.8 days - Average rainfall days in February:
14.9 days - Average rainfall days in March:
20 days - Average rainfall days in April:
22.9 days - Average rainfall days in May:
29.1 days - Average rainfall days in June:
28.9 days
- Average rainfall days in July:
29.9 days - Average rainfall days in August:
29.8 days - Average rainfall days in September:
29.7 days - Average rainfall days in October:
30.5 days - Average rainfall days in November:
28.5 days - Average rainfall days in December:
23 days
The month with the highest number of rainy days is October (30.5 days).
The month with the least rainy days is February (14.9 days).
Average daylight / Average sunshine
San Diego, Costa Rica
- Average daylight in January:
11h and 4min - Average daylight in February:
11h and 5min - Average daylight in March:
12h and 1min - Average daylight in April:
12h and 2min - Average daylight in May:
12h and 4min - Average daylight in June:
12h and 4min
- Average daylight in July:
12h and 4min - Average daylight in August:
12h and 2min - Average daylight in September:
12h and 1min - Average daylight in October:
11h and 5min - Average daylight in November:
11h and 4min - Average daylight in December:
11h and 4min
The month with the longest days is June (Average daylight: 12h and 42min).
The month with the shortest days is December (Average daylight: 11h and 36min).
- Average sunshine in January:
8h and 5min - Average sunshine in February:
9h and 1min - Average sunshine in March:
8h and 5min - Average sunshine in April:
8h and 4min - Average sunshine in May:
7h and 2min - Average sunshine in June:
6h and 5min
- Average sunshine in July:
7h and 4min - Average sunshine in August:
7h and 2min - Average sunshine in September:
7h and 2min - Average sunshine in October:
6h and 3min - Average sunshine in November:
6h and 5min - Average sunshine in December:
8h and 0min
The month with the most sunshine is February (Average sunshine: 9h and 6min).
The month with the least sunshine is October (Average sunshine: 6h and 30min).
Average sunshine days
San Diego, Costa Rica
- Average sunshine days in January:
9.2 days - Average sunshine days in February:
10.4 days - Average sunshine days in March:
6.9 days - Average sunshine days in April:
5.6 days - Average sunshine days in May:
1.2 days - Average sunshine days in June:
0.5 days
- Average sunshine days in July:
0.5 days - Average sunshine days in August:
0.4 days - Average sunshine days in September:
0.3 days - Average sunshine days in October:
0.1 days - Average sunshine days in November:
1 days - Average sunshine days in December:
4.9 days
The month with the most sunshine days is February (10.4 days).
The month with the least sunshine days is October (0.1 days).
Average UV index
San Diego, Costa Rica
The months with the highest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 5).
The months with the lowest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 5).
Average cloud cover
San Diego, Costa Rica
The month with the most cloud cover is October (Cloud cover 61).
The month with the least cloud cover is February (Cloud cover 31).
Average visibility
San Diego, Costa Rica
The months with the highest visibility are January, February and March (9km).
The months with the lowest visibility are September and October (6km).
San Diego, Costa Rica
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