Best year time to visit Herndon

General weather information about Herndon

Average annual temperature is 19.4 °C

Absolute maximum temperature: 37.9 °C

Absolute minimum temperature: -1.7 °C

Number of sunny days: 176 days

Number of rainy days: 189 days

Look at detailed online map of Herndon

* Weather data for Herndon United States is based on climate observations for 2026 year

Herndon air temperature forecast for each month

JanFebMarAprMayJunJulAugSepOctNovDec
Absolute maximum temperature (°C)23.928.429.031.033.135.237.637.933.529.226.624.0
Average daytime temperature (°C)17.320.922.525.627.431.534.934.329.524.519.316.2
Average temperature (°C)11.515.116.219.121.425.328.628.223.618.813.510.8
Average night temperature (°C)7.110.610.613.616.420.223.723.318.813.99.06.7
Absolute minimum temperature (°C)-1.70.90.16.39.116.620.620.414.17.5-0.9-1.7

Herndon monthly weather indicators

JanFebMarAprMayJunJulAugSepOctNovDec
Daylight maximum duration (h)10.011.012.013.014.014.014.013.012.011.010.010.0
Daylight mean duration (h)10.311.012.013.013.814.314.113.312.411.410.510.0
Daylight minimum duration (h)10.010.011.012.013.014.013.012.011.010.010.09.0
Sunshine mean duration (h)6.67.58.69.99.610.911.411.510.38.97.36.6
Precipitation (mm)1351189511466117125144497663130
Sunny days1612181311119615232022
Rainy days1516131720192225158109
Snow days000000000000

Herndon - weather forecast by months

Herndon weather in januaryHerndon weather in februaryHerndon weather in marchHerndon weather in aprilHerndon weather in mayHerndon weather in juneHerndon weather in julyHerndon weather in augustHerndon weather in septemberHerndon weather in octoberHerndon weather in novemberHerndon weather in december

Best time to visit Herndon:

The best time to visit Herndon during the most sunny months:

  • July — 11.4(h)
  • August — 11.5(h)

The largest precipitation sum in Herndon is at

  • January — 135(mm)
  • August — 144(mm)
  • December — 130(mm)

    • Weather forecast in the closest to Herndon admin centers

    Weather forecast in the closest towns to Herndon

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    Frequently asked questions

    When is the best time to visit Herndon?
    The historical weather data above shows the warmest, sunniest and driest months to help you choose the best time to visit Herndon.
    What is the weather like in Herndon?
    See average temperature, rainfall and daylight hours for Herndon by month in the table above.
    How many sunny days does Herndon have?
    The monthly weather statistics above show sunshine and rainfall patterns for Herndon throughout the year.