Weather in September
September brings the commencement of autumn to Viana do Castelo. Contrasting with the warmer temperature in August, the average high temperature declines to 24.8°C (76.6°F). The length of daylight noticeably shortens, sympathizing with the midnight blues of winter. The approaching cooler nights of October begin to set the tone for the rest of the year. A light jacket might be suitable for the evenings.
Note: Most people do not find pleasure in swimming when the water temperature is 18.3°C (64.9°F). Breathing becomes increasingly difficult to manage as the water temperature drops from 21°C (69.8°F) to 15°C (59°F).
On the first day of September, sunrise is at 07:01 and sunset at 20:08. On the last day of the month, sunrise is at 07:31 and sunset at 19:18 WEST.
Temperature
September's arrival brings an average high-temperature of a still moderately hot 24.8°C (76.6°F), demonstrating subtle variation from the preceding month. In the month of September, the average temperature dips to a moderate 13.7°C (56.7°F) during the night.Sea temperature
With an average sea temperature of 18.3°C (64.9°F), September is the month with the warmest seawater in Viana do Castelo.Note: Most people do not find pleasure in swimming when the water temperature is 18.3°C (64.9°F). Breathing becomes increasingly difficult to manage as the water temperature drops from 21°C (69.8°F) to 15°C (59°F).
Daylight
The average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 07:01 and sunset at 20:08. On the last day of the month, sunrise is at 07:31 and sunset at 19:18 WEST.
Updated: Feb 2, 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 usual temperature for Viana do Castelo in September?
Viana do Castelo in September has an average high-temperature of 24.8°C (76.6°F) and an average low-temperature of 13.7°C (56.7°F).
What is the month with the warmest sea water in Viana do Castelo?
With an average sea temperature of 18.3°C (64.9°F), September is the month with the warmest seawater in Viana do Castelo, Portugal.
How cold is the water in September in Viana do Castelo?
In Viana do Castelo, the average seawater temperature in September is 18.3°C (64.9°F). For most, swimming in 18.3°C (64.9°F) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 21°C (69.8°F) to 15°C (59°F).
How many hours of daylight does Viana do Castelo have in September?
The average day length in September in Viana do Castelo, Portugal, is 12h and 28min.
When are sunrise and sunset in September in Viana do Castelo?
On the first day of September in Viana do Castelo, Portugal, sunrise is at 07:01 and sunset at 20:08. On the last day of the month, sunrise is at 07:31 and sunset at 19:18 WEST.
Average temperature in September
Viana do Castelo, Portugal
- Average high temperature in September: 24.8°C
The warmest month (with the highest average high temperature) is August (26.4°C).
The month with the lowest average high temperature is January (14.6°C).
- Average low temperature in September: 13.7°C
The month with the highest average low temperature is July (15.3°C).
The coldest month (with the lowest average low temperature) is January (4.9°C).
Average sea temperature in September
Viana do Castelo, Portugal
- Average sea temperature in September: 18.3°C
The best month for swimming (with the highest average sea temperature) is September (18.3°C).
The coldest months (with the lowest average sea temperature) are February and March (13.8°C).
Average daylight in September
Viana do Castelo, Portugal
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
Viana do Castelo, Portugal
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