Glacier National Park records about 720mm of rain across roughly 88 wet days a year, which is a 24% chance on an average day. January is the wettest month at 75mm (10% of the annual total) and July the driest at 28mm. Local rain type: snow mix. Glacier NP gets heavy winter snow — Going-to-the-Sun Road opens in late June at earliest. Summer rain is light and brief.
Chance of rain on an average day: 24%
Rainfall climatology for Glacier National Park. 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 | 720mm |
| Rain days per year | 88 |
| Odds on an average day | 24% |
| Wettest month | January — 75mm over 12 days |
| Driest month | July — 28mm over 4 days |
| Rain type | snow mix |
| Best dry window | July through September offers the driest conditions and open roads. |
| Worst rain window | October through May brings heavy snow — most park roads are closed. |
January delivers 168% more rain than July (75mm vs 28mm). 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 Glacier National Park is spread through the year — there is no season you can rely on being dry.
Glacier National Park rain typically comes as discrete showers, so a compact umbrella and a flexible plan are usually enough.
Rain falls on about 12 days in January against 4 in July — 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 | 75mm | 12 | 40% | -2°C |
| February | 48mm | 7 | 23% | -2°C |
| March | 42mm | 6 | 20% | 2°C |
| April | 38mm | 6 | 20% | 8°C |
| May | 52mm | 8 | 27% | 15°C |
| June | 62mm | 10 | 33% | 21°C |
| July | 28mm | 4 | 13% | 25°C |
| August | 28mm | 4 | 13% | 25°C |
| September | 32mm | 5 | 17% | 21°C |
| October | 38mm | 6 | 20% | 15°C |
| November | 55mm | 8 | 27% | 8°C |
| December | 72mm | 11 | 37% | 2°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Glacier National Park 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.
Glacier National Park records rain on roughly 88 days a year — about a 24% chance on any given day — totalling around 720mm.
January, with about 75mm over 12 rain days. That is 10% of the entire year's rainfall in a single month.
July is the driest month at 28mm across roughly 4 days. July through September offers the driest conditions and open roads.
Glacier NP gets heavy winter snow — Going-to-the-Sun Road opens in late June at earliest. Summer rain is light and brief.
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.