April is one of the cooler months of the year in Helena, with average highs near 9.4°C and lows around -3°C (mean 3.2°C). It is about average for rainfall, averaging 51 mm of rainfall and 69% relative humidity across the period.
April is one of the cooler months of the year in Helena. Across 45 years of records, the warmest April in Helena was 1987 — when the month averaged 7.7°C — while the coldest was 2008 at -0.1°C. Typical April days reach 9.4°C with nights near -3°C. The long-term trend is cooling, about 0.2°C per decade.
April is about average for rainfall in Helena, averaging 51 mm of rainfall. The wettest April on record was 2011 with 83 mm, while the driest was 1987 at 20 mm.
Relative humidity in Helena during April averages 69%. The most humid April was 2009 at 77%, and the least humid was 1987 at 60%.
April receives about 4.9 kWh/m²/day of solar energy in Helena. The sunniest April was 1987 at 5.6 kWh/m²/day, and the cloudiest were 2011 and 2019 at 4.2.
Average wind speed in Helena during April is 1.5 m/s. The windiest Aprils were 2011 and 2013 at 1.8 m/s, while the calmest were 1998 and 2003 at 1.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 3.7°C | 3.2°C | 3.2°C | 3.2°C | 2.6°C | -1.1°C |
| Avg High | 10.2°C | 9.1°C | 9.6°C | 9.2°C | 8.9°C | -1.3°C |
| Avg Low | -2.8°C | -2.9°C | -3.3°C | -2.8°C | -3.7°C | -0.9°C |
| Avg Rain | 39 mm | 52 mm | 54 mm | 62 mm | 44 mm | +5 mm |
April temperatures in Helena have stayed relatively stable across the record.
April has ranged from a record low of -16.9°C (1982) to a record high of 25.9°C (1987).
Rainfall in April is about average for rainfall, averaging 51 mm, with a wettest year of 83 mm.
A good time to visit Helena
April is a good time to visit Helena, with days averaging 9.4°C and nights around -3°C (mean 3.2°C, cooler than Helena's yearly average) and moderate rainfall. July and August are marginally more temperate, but April still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 10.4°C | 3.8°C | -2.9°C | 19.5°C | -7.5°C | 36 mm | 68% | 1.5 m/s | 5.1 |
| 2024 | 10.8°C | 4.5°C | -1.8°C | 21.4°C | -8.2°C | 46 mm | 68% | 1.5 m/s | 4.8 |
| 2023 | 8.6°C | 2.1°C | -4.4°C | 23.1°C | -13.2°C | 57 mm | 70% | 1.5 m/s | 4.9 |
| 2022 | 5.8°C | 0.3°C | -5.3°C | 21.3°C | -14.9°C | 45 mm | 65% | 1.7 m/s | 4.6 |
| 2021 | 9.5°C | 3.0°C | -3.5°C | 21.9°C | -8.0°C | 34 mm | 67% | 1.5 m/s | 5.3 |
| 2020 | 8.2°C | 1.9°C | -4.4°C | 21.8°C | -12.0°C | 44 mm | 71% | 1.6 m/s | 5.2 |
| 2019 | 8.8°C | 3.4°C | -2.0°C | 18.8°C | -7.0°C | 77 mm | 75% | 1.5 m/s | 4.2 |
| 2018 | 9.1°C | 2.8°C | -3.4°C | 21.7°C | -11.3°C | 80 mm | 76% | 1.5 m/s | 4.7 |
| 2017 | 9.1°C | 3.4°C | -2.3°C | 16.3°C | -6.9°C | 67 mm | 73% | 1.5 m/s | 4.4 |
| 2016 | 13.0°C | 6.0°C | -0.9°C | 22.7°C | -7.4°C | 52 mm | 69% | 1.6 m/s | 5 |
| 2015 | 10.1°C | 3.8°C | -2.5°C | 22.2°C | -6.1°C | 38 mm | 67% | 1.4 m/s | 5.3 |
| 2014 | 8.7°C | 2.8°C | -3.2°C | 16.5°C | -6.8°C | 52 mm | 71% | 1.7 m/s | 5.1 |
| 2013 | 7.2°C | 1.4°C | -4.5°C | 17.8°C | -10.0°C | 42 mm | 69% | 1.8 m/s | 4.9 |
| 2012 | 11.9°C | 5.2°C | -1.4°C | 25.3°C | -7.5°C | 57 mm | 68% | 1.6 m/s | 4.9 |
| 2011 🌧️ | 5.2°C | 0.2°C | -4.8°C | 11.3°C | -8.0°C | 83 mm | 75% | 1.8 m/s | 4.2 |
| 2010 | 8.6°C | 2.8°C | -3.0°C | 19.4°C | -8.2°C | 71 mm | 70% | 1.7 m/s | 5 |
| 2009 | 7.2°C | 1.3°C | -4.7°C | 19.9°C | -11.8°C | 66 mm | 77% | 1.4 m/s | 4.9 |
| 2008 ❄️ | 6.0°C | -0.1°C | -6.1°C | 18.8°C | -12.4°C | 44 mm | 72% | 1.6 m/s | 5.2 |
| 2007 | 9.9°C | 3.6°C | -2.6°C | 22.0°C | -7.4°C | 49 mm | 71% | 1.5 m/s | 4.8 |
| 2006 | 11.1°C | 4.4°C | -2.2°C | 19.9°C | -8.5°C | 81 mm | 72% | 1.5 m/s | 4.8 |
| 2005 | 10.0°C | 3.3°C | -3.3°C | 19.7°C | -8.7°C | 50 mm | 68% | 1.6 m/s | 4.7 |
| 2004 | 12.2°C | 5.2°C | -1.8°C | 20.8°C | -7.0°C | 51 mm | 65% | 1.4 m/s | 5.2 |
| 2003 | 10.3°C | 4.1°C | -2.2°C | 20.0°C | -7.3°C | 72 mm | 71% | 1.2 m/s | 4.5 |
| 2002 | 8.2°C | 1.8°C | -4.5°C | 17.3°C | -14.3°C | 39 mm | 66% | 1.6 m/s | 4.8 |
| 2001 | 9.1°C | 3.0°C | -3.0°C | 22.5°C | -6.9°C | 50 mm | 67% | 1.6 m/s | 4.8 |
| 2000 | 12.4°C | 5.0°C | -2.3°C | 20.0°C | -6.7°C | 35 mm | 64% | 1.5 m/s | 5.1 |
| 1999 | 8.5°C | 2.5°C | -3.6°C | 19.6°C | -8.5°C | 41 mm | 67% | 1.5 m/s | 5.3 |
| 1998 | 10.0°C | 4.0°C | -2.1°C | 21.5°C | -5.7°C | 44 mm | 69% | 1.2 m/s | 5.1 |
| 1997 | 5.7°C | 0.2°C | -5.4°C | 16.8°C | -14.7°C | 54 mm | 76% | 1.6 m/s | 4.9 |
| 1996 | 9.0°C | 3.3°C | -2.5°C | 22.0°C | -4.7°C | 56 mm | 73% | 1.6 m/s | 4.6 |
| 1995 | 7.4°C | 1.8°C | -3.8°C | 16.2°C | -8.9°C | 67 mm | 72% | 1.4 m/s | 5.2 |
| 1994 | 10.9°C | 4.3°C | -2.3°C | 22.5°C | -7.3°C | 57 mm | 70% | 1.4 m/s | 4.5 |
| 1993 | 8.3°C | 2.7°C | -2.8°C | 15.6°C | -6.6°C | 61 mm | 71% | 1.4 m/s | 4.5 |
| 1992 | 12.5°C | 5.7°C | -1.1°C | 24.3°C | -5.9°C | 43 mm | 65% | 1.5 m/s | 4.9 |
| 1991 | 7.4°C | 2.3°C | -2.9°C | 18.0°C | -5.8°C | 55 mm | 70% | 1.7 m/s | 4.9 |
| 1990 | 11.6°C | 4.7°C | -2.3°C | 21.6°C | -7.5°C | 38 mm | 69% | 1.4 m/s | 5 |
| 1989 | 10.6°C | 4.0°C | -2.7°C | 23.4°C | -7.9°C | 47 mm | 67% | 1.6 m/s | 5 |
| 1988 | 12.5°C | 5.3°C | -1.9°C | 23.3°C | -7.3°C | 46 mm | 64% | 1.4 m/s | 4.9 |
| 1987 🔥 | 15.8°C | 7.7°C | -0.4°C | 25.9°C | -5.8°C | 20 mm | 60% | 1.4 m/s | 5.6 |
| 1986 | 9.1°C | 2.8°C | -3.4°C | 19.7°C | -10.3°C | 50 mm | 70% | 1.6 m/s | 4.9 |
| 1985 | 11.6°C | 4.9°C | -1.8°C | 21.9°C | -6.1°C | 24 mm | 64% | 1.7 m/s | 5.3 |
| 1984 | 8.3°C | 2.3°C | -3.7°C | 22.9°C | -9.6°C | 53 mm | 69% | 1.5 m/s | 4.6 |
| 1983 | 8.1°C | 2.3°C | -3.5°C | 17.6°C | -9.0°C | 29 mm | 66% | 1.3 m/s | — |
| 1982 | 6.4°C | 0.6°C | -5.2°C | 18.4°C | -16.9°C | 41 mm | 69% | 1.6 m/s | — |
| 1981 | 9.5°C | 3.6°C | -2.4°C | 21.2°C | -7.0°C | 38 mm | 67% | 1.7 m/s | — |
Actual recorded April data for each year, 1981–2025 — sourced from NASA POWER.
The average high in April is around 9.4°C with lows near -3°C (mean 3.2°C), based on 45 years of NASA POWER data.
April averages 51 mm of rainfall in Helena, about average for rainfall. The wettest on record was 83 mm in 2011.
The hottest April reached 25.9°C in 1987. The coldest dipped to -16.9°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average April temperatures have held steady by about 0°C — but days and nights have moved in opposite directions. Daytime highs rose from 8.8°C to 9°C while overnight lows fell from -3.3°C to -3.6°C, widening the gap between day and night.
April is one of the cooler months of the year in Helena and about average for rainfall, so plan for around 9.4°C daytime highs and -3°C at night.
Not quite — April is the 6th coolest month in Helena, averaging 3.2°C.
For April in Helena, pack warm layers and a jacket for chilly mornings, with typical highs of 9.4°C and lows of -3°C. Bring an umbrella or light rain jacket too.
Relative humidity in April averages 69% — moderately humid.
Average wind speed in April is 1.5 m/s. The windiest April on record averaged 1.8 m/s (2011).
The wettest April on record was 2011 with 83 mm. On average, April sees 51 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Helena behaves each April, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for April specifically, along with year-by-year records and how the month has changed over the decades.
