September weather forecastCacilhas, Portugal
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Cacilhas, Portugal, with temperature in the range of an average low of 18.2°C (64.8°F) and an average high of 23.6°C (74.5°F).Temperature
Cacilhas's weather in September displays an average high-temperature of a still warm 23.6°C (74.5°F), showing minor disparity from August's 24.5°C (76.1°F). Cacilhas observes an average low-temperature of 18.2°C (64.8°F) during September nights.Humidity
In September, the average relative humidity in Cacilhas is 73%.Rainfall
In Cacilhas, Portugal, in September, during 4.9 rainfall days, 10mm (0.39") of precipitation is typically accumulated. In Cacilhas, during the entire year, the rain falls for 85.8 days and collects up to 215mm (8.46") of precipitation.Sea temperature
With an average sea temperature of 19.9°C (67.8°F), September is the month with the warmest seawater in Cacilhas.Note: For most people, a water temperature of 19.9°C (67.8°F) is not conducive to enjoyable swimming. Breathing control becomes harder as the water temperature dips below 21°C (69.8°F).
Daylight
In September, the average length of the day in Cacilhas, Portugal, is 12h and 26min.On the first day of September, sunrise is at 07:06 and sunset at 20:06. On the last day of the month, sunrise is at 07:32 and sunset at 19:20 WEST.
Sunshine
In September, the average sunshine in Cacilhas is 9.4h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV radiation for the average person.Note: The maximum daily UV index, 6 in September, converts into the following recommendations:
Persist with safeguards and heed sun safety doctrines. Keeping sunburn at bay is of prime importance. The time between 10 a.m. and 4 p.m. is when UV radiation is at its peak. Limit exposure to direct sunlight during these hours. Experience reduced UV exposure by about half when donning a wide-brim hat.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Cacilhas, Portugal
- Average high temperature in September: 23.6°C
The warmest month (with the highest average high temperature) is August (24.5°C).
The month with the lowest average high temperature is January (14.8°C).
- Average low temperature in September: 18.2°C
The month with the highest average low temperature is August (18.6°C).
The coldest month (with the lowest average low temperature) is February (10.8°C).
Average pressure in September
Cacilhas, Portugal
- Average pressure in September: 1017mbar
The months with the highest atmospheric pressure are January and December (1022.5mbar).
The month with the lowest atmospheric pressure is April (1015.7mbar).
Average wind speed in September
Cacilhas, Portugal
- Average wind speed in September: 15.8km/h
The windiest month (with the highest average wind speed) is February (19.5km/h).
The calmest month (with the lowest average wind speed) is October (15.6km/h).
Average humidity in September
Cacilhas, Portugal
- Average humidity in September: 73%
The months with the highest relative humidity are January, April, July and December (75%).
The months with the lowest relative humidity are May and October (72%).
Average rainfall in September
Cacilhas, Portugal
- Average rainfall in September: 10mm
The wettest month (with the highest rainfall) is November (44mm).
The driest month (with the least rainfall) is July (2mm).
Average rainfall days in September
Cacilhas, Portugal
- Average rainfall days in September: 4.9 days
The month with the highest number of rainy days is November (12.4 days).
The month with the least rainy days is August (1.9 days).
Average sea temperature in September
Cacilhas, Portugal
- Average sea temperature in September: 19.9°C
The best month for swimming (with the highest average sea temperature) is September (19.9°C).
The coldest month (with the lowest average sea temperature) is March (15.1°C).
Average daylight in September /
Average sunshine in September
Cacilhas, Portugal
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 24min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is January (Average sunshine: 5h and 30min).
Average sunshine days in September
Cacilhas, Portugal
- Average sunshine days in September: 24.5 days
The month with the most sunshine days is August (28 days).
The month with the least sunshine days is November (15.6 days).
Average UV index in September
Cacilhas, Portugal
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 4).
Average cloud cover in September
Cacilhas, Portugal
- Average cloud cover in September: 16
The month with the most cloud cover is January (Cloud cover 40).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in September
Cacilhas, Portugal
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).





