Climate averages 1991–2020
Arlington (Virginia), United States weather
in September.
A warm, wet month: the 4th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Arlington (Virginia), United States: daytime highs average 25.4°C and nights cool to about 16.5°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 110 mm of rain on roughly 9 days, which makes September a wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 12 h 29 min on an average September day.
The nearest other city in this atlas is Washington (6 km away). In September its highs average 26.0°C, 0.5°C warmer than Arlington (Virginia), United States, with 110 mm of rain.
Among the 498 cities listed in the United States, Arlington (Virginia), United States ranks joint 297th of 498 for the warmest September highs and joint 425th of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Arlington (Virginia), United States is 1.5°C cooler than that mean.
From September to October, average highs fall by 6.3°C to 19.1°C, and monthly rainfall falls from 110 mm to 86 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Arlington (Virginia), United States climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 5.5°C-2.6°C | -2.6°C | 78 | 8.6 | 9.810 h |
| February | 7.4°C-2.0°C | -2.0°C | 74 | 8.5 | 10.711 h |
| March | 12.0°C1.7°C | 1.7°C | 99 | 10.3 | 11.912 h |
| April | 18.3°C7.3°C | 7.3°C | 86 | 10.1 | 13.213 h |
| May | 23.1°C12.9°C | 12.9°C | 95 | 11.0 | 14.314 h |
| June | 28.0°C18.1°C | 18.1°C | 90 | 11.2 | 14.815 h |
| July | 30.5°C20.9°C | 20.9°C | 103 | 12.1 | 14.615 h |
| August | 29.3°C20.1°C | 20.1°C | 89 | 10.1 | 13.714 h |
| September, selected | 25.4°C16.5°C | 16.5°C | 110 | 9.2 | 12.512 h |
| October | 19.1°C10.1°C | 10.1°C | 86 | 7.8 | 11.211 h |
| November | 12.9°C4.2°C | 4.2°C | 74 | 7.5 | 10.110 h |
| December | 7.6°C-0.2°C | -0.2°C | 90 | 8.8 | 9.59 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Washington in SeptemberUnited States · 6 kmHigh 26.0°C · Low 17.0°C · 110 mm rain
- Alexandria, United States in SeptemberUnited States · 10 kmHigh 25.7°C · Low 17.2°C · 106 mm rain
- Silver Spring in SeptemberUnited States · 14 kmHigh 25.2°C · Low 16.5°C · 110 mm rain
- Centreville in SeptemberUnited States · 28 kmHigh 25.3°C · Low 16.8°C · 111 mm rain
- Germantown in SeptemberUnited States · 36 kmHigh 25.1°C · Low 16.0°C · 113 mm rain
- Columbia (Maryland), United States in SeptemberUnited States · 46 kmHigh 24.6°C · Low 16.6°C · 116 mm rain
- Baltimore in SeptemberUnited States · 62 kmHigh 24.8°C · Low 16.6°C · 120 mm rain
- Richmond in SeptemberUnited States · 151 kmHigh 26.3°C · Low 17.3°C · 112 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Arlington) is explained once on the Arlington (Virginia), United States year overview and on the Sources, method and limits page.
Washington and Silver Spring lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.