Washington DC records about 1003mm of rain across roughly 113 wet days a year, which is a 31% chance on an average day. July is the wettest month at 100mm (10% of the annual total) and February the driest at 66mm. Local rain type: thunderstorms. DC summers are hot and stormy — afternoon thunderstorms from June through August are near-daily events. The Smithsonian museums are perfect storm shelters.
Chance of rain on an average day: 31%
Rainfall climatology for Washington DC. The live hour-by-hour answer for today loads at the top of this page from Open-Meteo and refreshes through the day — the figures below describe a typical year, not today.
Last updated: · Live forecast data refreshes hourly.
| Annual rainfall | 1003mm |
| Rain days per year | 113 |
| Odds on an average day | 31% |
| Wettest month | July — 100mm over 11 days |
| Driest month | February — 66mm over 7 days |
| Rain type | thunderstorms |
| Best dry window | October offers the driest, most comfortable weather for monument visits and outdoor exploration. |
| Worst rain window | June through August brings intense afternoon thunderstorms combined with oppressive humidity. |
July delivers 52% more rain than February (100mm vs 66mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 10% of the annual total, so rain in Washington DC is spread through the year — there is no season you can rely on being dry.
Washington DC rain arrives in short, heavy bursts — shelter and timing matter more than gear.
Rain falls on about 11 days in July against 7 in February — the frequency swing matters more for planning than the millimetre totals.
Climate normals. Use them to judge whether today's live forecast at the top of the page is typical or unusual for the season.
| Month | Rainfall | Rain days | Chance on a given day | Highs |
|---|---|---|---|---|
| January | 71mm | 8 | 27% | 6°C |
| February | 66mm | 7 | 23% | 6°C |
| March | 89mm | 10 | 33% | 10°C |
| April | 76mm | 9 | 30% | 15°C |
| May | 98mm | 11 | 37% | 22°C |
| June | 96mm | 11 | 37% | 27°C |
| July | 100mm | 11 | 37% | 31°C |
| August | 79mm | 9 | 30% | 31°C |
| September | 94mm | 11 | 37% | 27°C |
| October | 86mm | 10 | 33% | 22°C |
| November | 73mm | 8 | 27% | 15°C |
| December | 77mm | 9 | 30% | 10°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Washington DC we combine the hourly probability curve, expected volume in millimetres, and the city's own rainfall record into a single umbrella verdict.
| Factor | Weight | What it measures |
|---|---|---|
| Hourly probability | 40% | Peak and sustained chance of measurable rain across the next 24 hours. |
| Expected volume | 30% | Total millimetres, which separates a passing shower from a genuine soaking. |
| Timing & duration | 20% | When rain starts, when it eases, and the longest continuous dry window. |
| Local rain type | 10% | Drizzle, brief showers, thunderstorms or monsoon — each needs different gear. |
Live hourly values come from Open-Meteo and refresh through the day. Monthly rainfall figures are climate normals, so they describe a typical year rather than a forecast.
Washington DC records rain on roughly 113 days a year — about a 31% chance on any given day — totalling around 1003mm.
July, with about 100mm over 11 rain days. That is 10% of the entire year's rainfall in a single month.
February is the driest month at 66mm across roughly 7 days. October offers the driest, most comfortable weather for monument visits and outdoor exploration.
DC summers are hot and stormy — afternoon thunderstorms from June through August are near-daily events. The Smithsonian museums are perfect storm shelters.
No. Probability is the chance that at least 0.2mm of rain falls at your location at some point in the period. Check the expected millimetres alongside it: 40% with 0.4mm is a passing shower, 40% with 12mm is a soaking.