Oklahoma City records about 789mm of rain across roughly 107 wet days a year, which is a 29% chance on an average day. May is the wettest month at 111mm (14% of the annual total) and October the driest at 42mm. Local rain type: brief showers.
Chance of rain on an average day: 29%
Rainfall climatology for Oklahoma City. 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 | 789mm |
| Rain days per year | 107 |
| Odds on an average day | 29% |
| Wettest month | May — 111mm over 12 days |
| Driest month | October — 42mm over 7 days |
| Rain type | brief showers |
| Best dry window | October is the most reliable dry stretch of the year. |
| Worst rain window | May carries the highest chance of a washed-out day. |
May delivers 164% more rain than October (111mm vs 42mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 14% of the annual total, so rain in Oklahoma City is spread through the year — there is no season you can rely on being dry.
Oklahoma City rain typically comes as discrete showers, so a compact umbrella and a flexible plan are usually enough.
Rain falls on about 12 days in May against 7 in October — 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 | 54mm | 9 | 30% | 12°C |
| February | 54mm | 9 | 30% | 13°C |
| March | 66mm | 11 | 37% | 18°C |
| April | 78mm | 13 | 43% | 23°C |
| May | 111mm | 12 | 40% | 29°C |
| June | 93mm | 10 | 33% | 33°C |
| July | 57mm | 6 | 20% | 34°C |
| August | 57mm | 6 | 20% | 33°C |
| September | 93mm | 10 | 33% | 29°C |
| October | 42mm | 7 | 23% | 23°C |
| November | 42mm | 7 | 23% | 18°C |
| December | 42mm | 7 | 23% | 13°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Oklahoma City 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.
Oklahoma City records rain on roughly 107 days a year — about a 29% chance on any given day — totalling around 789mm.
May, with about 111mm over 12 rain days. That is 14% of the entire year's rainfall in a single month.
October is the driest month at 42mm across roughly 7 days.
With rain on about 29% of days and brief showers as the dominant type, a compact umbrella or waterproof shell is worth packing for Oklahoma City outside October.
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.