Yellowstone records about 423mm of rain across roughly 72 wet days a year, which is a 20% chance on an average day. May is the wettest month at 48mm (11% of the annual total) and February the driest at 19mm. Local rain type: snow mix. Yellowstone gets snow from October through May — summer brings brief afternoon thunderstorms. Roads close seasonally due to snow.
Chance of rain on an average day: 20%
Rainfall climatology for Yellowstone. 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 | 423mm |
| Rain days per year | 72 |
| Odds on an average day | 20% |
| Wettest month | May — 48mm over 10 days |
| Driest month | February — 19mm over 4 days |
| Rain type | snow mix |
| Best dry window | July and August offer the warmest, driest conditions for wildlife viewing. |
| Worst rain window | October through May can bring heavy snow that closes roads — check road status before visiting. |
May delivers 153% more rain than February (48mm vs 19mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 11% of the annual total, so rain in Yellowstone is spread through the year — there is no season you can rely on being dry.
Yellowstone rain typically comes as discrete showers, so a compact umbrella and a flexible plan are usually enough.
Rain falls on about 10 days in May against 4 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 | 23mm | 5 | 17% | -2°C |
| February | 19mm | 4 | 13% | -2°C |
| March | 26mm | 6 | 20% | 1°C |
| April | 30mm | 6 | 20% | 8°C |
| May | 48mm | 10 | 33% | 16°C |
| June | 38mm | 8 | 27% | 23°C |
| July | 30mm | 6 | 20% | 26°C |
| August | 22mm | 5 | 17% | 26°C |
| September | 24mm | 5 | 17% | 23°C |
| October | 22mm | 5 | 17% | 16°C |
| November | 30mm | 6 | 20% | 8°C |
| December | 28mm | 6 | 20% | 1°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Yellowstone 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.
Yellowstone records rain on roughly 72 days a year — about a 20% chance on any given day — totalling around 423mm.
May, with about 48mm over 10 rain days. That is 11% of the entire year's rainfall in a single month.
February is the driest month at 19mm across roughly 4 days. July and August offer the warmest, driest conditions for wildlife viewing.
Yellowstone gets snow from October through May — summer brings brief afternoon thunderstorms. Roads close seasonally due to snow.
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.