Normandy

Hérouville-Saint-Clair, France Climate

NASA POWER reanalysis for the half-degree grid cell around Hérouville-Saint-Clair, 1991-2020; a grid cell is an area average and can differ from a thermometer in town by several degrees

The warmest month is August, with an average high of 23°C; the coldest is February, with an average low of 2°C. A normal year brings 757 mm of precipitation.

Temperature through the year

The normal daily high and low. The line marks today.

Normal daily high and low temperature at Hérouville-Saint-Clair through the year, in °C, with the record for each date.-20-10010203040JanFebMarAprMayJunJulAugSepOctNovDec
  • Normal low
  • Normal high
  • Reanalysis extreme high
  • Reanalysis extreme low

Normals for Sep 25

Normal high
19°C
Normal low
10°C
Reanalysis high
23°Cin 2013
Reanalysis low
4°Cin 2018
Chance of a wet day
45%
Daylight
12 h 01 min

Month by month

Averages for 1991-2020. Wet days have at least 1 mm of precipitation in the reanalysis. Each month links to its own page.

MonthAvg highAvg lowWarmestColdestPrecipitationWet days
January7°C2°C15°C (1993)-9°C (1997)68 mm15.5
February8°C2°C19°C (2019)-12°C (1991)57 mm11.3
March11°C3°C21°C (2005)-5°C (2018)53 mm12.4
April14°C5°C26°C (2018)-4°C (2003)51 mm12.0
May17°C8°C28°C (2005)0°C (1996)59 mm12.4
June20°C11°C33°C (2019)4°C (2001)57 mm12.0
July22°C13°C35°C (2019)7°C (2000)56 mm12.4
August23°C13°C37°C (2003)8°C (2014)56 mm12.4
September20°C11°C31°C (2005)4°C (2018)57 mm12.0
October16°C8°C27°C (2011)-4°C (1997)78 mm15.5
November11°C5°C19°C (2015)-5°C (1993)78 mm15.0
December8°C2°C16°C (1998)-11°C (1996)87 mm15.5
Year15°C7°C757 mm158

Precipitation

Rain and melted snow together. The chance of a wet day is the share of days with at least 1 mm of precipitation in the reanalysis.

757 mm in a normal year, most in December.

Chance of a wet day

The chance of at least 1 mm of precipitation in the reanalysis on each date at Hérouville-Saint-Clair, in percent.0204060JanFebMarAprMayJunJulAugSepOctNovDec
  • Chance of a wet day

Humidity and comfort

NASA POWER reanalysis, 1991-2020, for the grid cell around Hérouville-Saint-Clair.

The muggiest month is June, when 1 percent of days are muggy or worse, with a mean dew point of 18°C or more.

MonthDew pointHumidityDryComfortableHumidMuggyOppressiveMiserable
January3°C92%100%0%0%0%0%0%
February3°C89%100%0%0%0%0%0%
March5°C85%100%0%0%0%0%0%
April6°C81%99%1%0%0%0%0%
May9°C80%90%9%1%0%0%0%
June12°C79%67%25%7%1%0%0%
July13°C78%43%42%14%1%0%0%
August14°C78%39%43%16%1%0%0%
September11°C80%69%28%4%0%0%0%
October9°C86%87%12%0%0%0%0%
November6°C91%99%1%0%0%0%0%
December4°C93%100%0%0%0%0%0%

Comfort is judged by the day's mean dew point: dry below 13°C, comfortable to 16°C, humid to 18°C, muggy to 21°C, oppressive to 24°C, miserable above.

Clouds

Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.

The clearest month is July, with the sky 62 percent covered on average; the cloudiest is December, at 77 percent.

Wind

The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.

The windiest month is January, averaging 22.0 km/h at 10 meters (33 feet) above the ground.

Daylight and sunshine

The longest day is Jun 18, with 16 h 15 min of daylight; the shortest is Dec 19, with 8 h 11 min.

Hours of daylight at Hérouville-Saint-Clair through the year.0510152025JanFebMarAprMayJunJulAugSepOctNovDec
  • Day length

Solar energy

Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.

Sunrise and sunset calendar

Month pages

The weather in Hérouville-Saint-Clair in each month, day by day.

What this means

A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.

Where no station record is within reach, the extremes shown are the highest and lowest the reanalysis produced for the date in 1991-2020, not measured records.

Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.

More for this place

Nearby

Sources

Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.