Best time to visit Helena
The best time to visit Helena is June–September, judged on twenty years of weather records and the events worth going for.
Helena, Montana, United States
°C
mm
- Average daily high and low
- Precipitation
- Good month
- Best month
- Made good or best by an event
| Month | Average daily high | Average daily low | Precipitation | Verdict |
|---|---|---|---|---|
| January | -2.4 °C / 28 °F | -10.8 °C / 13 °F | 25 mm / 1 in | neither best nor good |
| February | -2 °C / 28 °F | -11.2 °C / 12 °F | 30 mm / 1.2 in | neither best nor good |
| March | 3.9 °C / 39 °F | -6.2 °C / 21 °F | 37 mm / 1.5 in | neither best nor good |
| April | 8.6 °C / 47 °F | -2.7 °C / 27 °F | 56 mm / 2.2 in | neither best nor good |
| May | 14.9 °C / 59 °F | 2.9 °C / 37 °F | 83 mm / 3.3 in | good month |
| June | 20.6 °C / 69 °F | 7.2 °C / 45 °F | 85 mm / 3.3 in | best month |
| July | 27.3 °C / 81 °F | 10.8 °C / 51 °F | 35 mm / 1.4 in | best month |
| August | 26.1 °C / 79 °F | 10.3 °C / 51 °F | 36 mm / 1.4 in | best month |
| September | 20.6 °C / 69 °F | 6.5 °C / 44 °F | 44 mm / 1.7 in | best month |
| October | 11.2 °C / 52 °F | 0.2 °C / 32 °F | 40 mm / 1.6 in | neither best nor good |
| November | 3.2 °C / 38 °F | -5.7 °C / 22 °F | 30 mm / 1.2 in | neither best nor good |
| December | -2.4 °C / 28 °F | -10.7 °C / 13 °F | 30 mm / 1.2 in | neither best nor good |
Good and best months depend on more than temperature, rain and events. How they are chosen
Each activity on this page has its own good and best months, rated on twenty years of daily weather records. Which measures count, and how much, depends on the activity: humidity for exploring outdoors, wind for the beach, hiking and skiing, snow for skiing alone. Between them, the activities are rated on:
- Daytime highs
- Night-time lows
- How warm it feels
- Humidity
- How much of the day is sunny
- Hours of daylight
- Monthly rainfall
- How many days it rains
- Days of heavy rain
- Wind
- Snowfall and days with snow
- Major events, such as festivals
The chart shows the good and best months for exploring outdoors.
The event icon marks a month that an event lifts to good or best, such as a festival or a natural spectacle. Choose “Weather only” in the toolbar to rate the months on weather alone.
Best months by activity
Exploring outdoors
Mild days and nights, mostly dry and bright. The default for 'when should I go'.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: neither
- MMay: good
- JJune: best
- JJuly: best
- AAugust: best
- SSeptember: best
- OOctober: neither
- NNovember: neither
- DDecember: neither
- Best
- June–September
- Good
- May
Why these months
May · good
In its favour: share of daylight that is sunny 80%, precipitation 83 mm / 3.3 in, feels like (high) 12.5 °C / 55 °F, average daily high 14.9 °C / 59 °F, days with heavy rain 2.2 days, relative humidity 65%.
Against: wet days 14.1 days, average daily low 2.9 °C / 37 °F.
June · best
In its favour: feels like (high) 19.2 °C / 67 °F, average daily high 20.6 °C / 69 °F, share of daylight that is sunny 83%, precipitation 85 mm / 3.3 in, days with heavy rain 2.5 days, relative humidity 62%, average daily low 7.2 °C / 45 °F.
Against: wet days 12.8 days.
July · best
In its favour: feels like (high) 26.3 °C / 79 °F, precipitation 35 mm / 1.4 in, share of daylight that is sunny 92%, average daily high 27.3 °C / 81 °F, days with heavy rain 0.8 days, wet days 8.2 days, average daily low 10.8 °C / 51 °F, relative humidity 51%.
August · best
In its favour: feels like (high) 24.3 °C / 76 °F, precipitation 36 mm / 1.4 in, share of daylight that is sunny 90%, average daily high 26.1 °C / 79 °F, days with heavy rain 0.7 days, wet days 7 days, average daily low 10.3 °C / 51 °F, relative humidity 49%.
September · best
In its favour: feels like (high) 17.7 °C / 64 °F, average daily high 20.6 °C / 69 °F, precipitation 44 mm / 1.7 in, share of daylight that is sunny 86%, wet days 6.5 days, days with heavy rain 1.6 days, relative humidity 55%, average daily low 6.5 °C / 44 °F.
Hiking and trekking
Cool enough to climb in, dry enough to enjoy, long enough days.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: good
- MMay: best
- JJune: best
- JJuly: good
- AAugust: best
- SSeptember: best
- OOctober: best
- NNovember: neither
- DDecember: neither
- Best
- May–June, August–October
- Good
- April, July
Why these months
April · good
In its favour: precipitation 56 mm / 2.2 in, days with heavy rain 1 days, average daily high 8.6 °C / 47 °F, share of daylight that is sunny 82%, daylight per day 13.6 h, wet days 10.9 days, wind (daily max) 14 km/h / 9 mph.
Against: average daily low -2.7 °C / 27 °F, feels like (high) 5.3 °C / 42 °F.
May · best
In its favour: average daily high 14.9 °C / 59 °F, precipitation 83 mm / 3.3 in, days with heavy rain 2.2 days, feels like (high) 12.5 °C / 55 °F, share of daylight that is sunny 80%, daylight per day 15 h, average daily low 2.9 °C / 37 °F, wind (daily max) 13 km/h / 8 mph.
Against: wet days 14.1 days.
June · best
In its favour: average daily high 20.6 °C / 69 °F, precipitation 85 mm / 3.3 in, feels like (high) 19.2 °C / 67 °F, average daily low 7.2 °C / 45 °F, share of daylight that is sunny 83%, daylight per day 15.8 h, days with heavy rain 2.5 days, wind (daily max) 14 km/h / 8 mph.
Against: wet days 12.8 days.
July · good
In its favour: precipitation 35 mm / 1.4 in, days with heavy rain 0.8 days, wet days 8.2 days, average daily low 10.8 °C / 51 °F, share of daylight that is sunny 92%, daylight per day 15.4 h, wind (daily max) 12 km/h / 8 mph.
Against: average daily high 27.3 °C / 81 °F, feels like (high) 26.3 °C / 79 °F.
August · best
In its favour: precipitation 36 mm / 1.4 in, wet days 7 days, days with heavy rain 0.7 days, average daily low 10.3 °C / 51 °F, share of daylight that is sunny 90%, daylight per day 14.1 h, feels like (high) 24.3 °C / 76 °F, wind (daily max) 13 km/h / 8 mph.
Against: average daily high 26.1 °C / 79 °F.
September · best
In its favour: average daily high 20.6 °C / 69 °F, precipitation 44 mm / 1.7 in, wet days 6.5 days, days with heavy rain 1.6 days, feels like (high) 17.7 °C / 64 °F, average daily low 6.5 °C / 44 °F, share of daylight that is sunny 86%, daylight per day 12.5 h, wind (daily max) 13 km/h / 8 mph.
October · best
In its favour: average daily high 11.2 °C / 52 °F, precipitation 40 mm / 1.6 in, days with heavy rain 0.8 days, wet days 8.3 days, share of daylight that is sunny 81%, daylight per day 10.9 h, feels like (high) 7.5 °C / 46 °F, wind (daily max) 14 km/h / 9 mph, average daily low 0.2 °C / 32 °F.
Skiing and snow
Wants cold and snowfall; sunshine barely matters.
- JJanuary: best
- FFebruary: best
- MMarch: best
- AApril: best
- MMay: neither
- JJune: neither
- JJuly: neither
- AAugust: neither
- SSeptember: neither
- OOctober: good
- NNovember: best
- DDecember: best
- Best
- November–April
- Good
- October
Why these months
January · best
In its favour: average daily high -2.4 °C / 28 °F, days with snow 14.3 days, snowfall 18 cm / 7.1 in, average daily low -10.8 °C / 13 °F, wind (daily max) 13 km/h / 8 mph, daylight per day 9.1 h.
February · best
In its favour: average daily high -2 °C / 28 °F, snowfall 21 cm / 8.4 in, days with snow 16.6 days, average daily low -11.2 °C / 12 °F, wind (daily max) 13 km/h / 8 mph, daylight per day 10.3 h.
March · best
In its favour: snowfall 20 cm / 8 in, days with snow 13.9 days, average daily high 3.9 °C / 39 °F, average daily low -6.2 °C / 21 °F, wind (daily max) 13 km/h / 8 mph, daylight per day 11.9 h.
April · best
In its favour: snowfall 24 cm / 9.3 in, days with snow 13 days, average daily low -2.7 °C / 27 °F, wind (daily max) 14 km/h / 9 mph, daylight per day 13.6 h.
Against: average daily high 8.6 °C / 47 °F.
October · good
In its favour: days with snow 5.8 days, wind (daily max) 14 km/h / 9 mph, daylight per day 10.9 h.
Against: average daily high 11.2 °C / 52 °F, snowfall 12 cm / 4.8 in, average daily low 0.2 °C / 32 °F.
November · best
In its favour: days with snow 10.2 days, average daily high 3.2 °C / 38 °F, average daily low -5.7 °C / 22 °F, wind (daily max) 14 km/h / 9 mph, daylight per day 9.4 h.
Against: snowfall 16 cm / 6.1 in.
December · best
In its favour: average daily high -2.4 °C / 28 °F, snowfall 20 cm / 8 in, days with snow 15.3 days, average daily low -10.7 °C / 13 °F, wind (daily max) 13 km/h / 8 mph, daylight per day 8.6 h.
An activity is listed only where it applies: skiing at ski destinations, beach and swimming at beach destinations. The nearest ski area is Great Divide Ski Area, 28 km away.
Weather averages
Monthly averages over twenty years, 2006–2025. Highs, lows and precipitation are in the chart at the top.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels like (high) | -6.7 °C | -6.2 °C | 0.2 °C | 5.3 °C | 12.5 °C | 19.2 °C | 26.3 °C | 24.3 °C | 17.7 °C | 7.5 °C | -0.9 °C | -6.6 °C |
| Days with heavy rain | 0.2 days | 0.2 days | 0.6 days | 1 days | 2.2 days | 2.5 days | 0.8 days | 0.7 days | 1.6 days | 0.8 days | 0.3 days | 0.1 days |
| Time rain usually falls | 10 pm | 5 am | 12 am | 6 pm | 5 pm | 5 pm | 6 pm | 6 pm | 6 pm | 9 am | 8 am | 10 am |
| Sunshine per day | 7 h | 8.1 h | 10 h | 11.1 h | 12.1 h | 13.2 h | 14.2 h | 12.6 h | 10.7 h | 8.8 h | 7.3 h | 6.4 h |
| Relative humidity | 77% | 75% | 71% | 66% | 65% | 62% | 51% | 49% | 55% | 66% | 71% | 77% |
Air quality
Averaged over a shorter period (2022–2025) than the twenty-year averages above, and not counted towards good or best months.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Air pollution (PM2.5) 2022–2025 | 3.6 µg/m³ | 5.1 µg/m³ | 8.2 µg/m³ | 10.2 µg/m³ | 8.9 µg/m³ | 8.1 µg/m³ | 8.6 µg/m³ | 8.6 µg/m³ | 9.6 µg/m³ | 4.4 µg/m³ | 4.4 µg/m³ | 6.6 µg/m³ |
| Air pollution (PM2.5, daily peak) 2022–2025 | 6.6 µg/m³ | 8.5 µg/m³ | 13.9 µg/m³ | 16.1 µg/m³ | 14 µg/m³ | 13 µg/m³ | 14.2 µg/m³ | 14 µg/m³ | 15.6 µg/m³ | 7.7 µg/m³ | 7.5 µg/m³ | 14.4 µg/m³ |
- Good 15 µg/m³ or less
- Fair 15 to 25 µg/m³
- Moderate 25 to 37.5 µg/m³
- Poor 37.5 to 50 µg/m³
- Very poor 50 to 75 µg/m³
- Extremely poor over 75 µg/m³
Each figure is compared with the World Health Organization's guideline for a day's air, 15 µg/m³ or less, and with its interim targets above that. The words are ours: the WHO does not name its steps. The figures are modelled monthly averages, so single days can be well above them. The daily peak is the average of each day's highest hour, shaded on the same scale.