June is one of the warmer months of the year in Boulder, with average highs near 28.4°C and lows around 11.8°C (mean 20.1°C). It is about average for rainfall, averaging 47 mm of rainfall and 43% relative humidity across the period.
June is one of the warmer months of the year in Boulder. Across 45 years of records, the warmest June in Boulder was 2012 — when the month averaged 24.1°C — while the coldest was 1983 at 16.3°C. Typical June days reach 28.4°C with nights near 11.8°C. The long-term trend is warming, about 0.6°C per decade.
June is about average for rainfall in Boulder, averaging 47 mm of rainfall. The wettest June on record was 2023 with 121 mm, while the driest was 1990 at 10 mm.
Relative humidity in Boulder during June averages 43%. The most humid June was 2023 at 59%, and the least humid was 2012 at 28%.
June receives about 6.9 kWh/m²/day of solar energy in Boulder. The sunniest Junes were 2012 and 2013 at 7.5 kWh/m²/day, and the cloudiest was 1992 at 5.9.
Average wind speed in Boulder during June is 2.2 m/s. The windiest June was 2012 at 2.7 m/s, while the calmest was 2009 at 1.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 19.2°C | 19.3°C | 20.1°C | 21.1°C | 21.3°C | +2.1°C |
| Avg High | 27.2°C | 27.6°C | 28.5°C | 29.6°C | 29.5°C | +2.3°C |
| Avg Low | 11.3°C | 11.1°C | 11.6°C | 12.6°C | 13.0°C | +1.7°C |
| Avg Rain | 54 mm | 49 mm | 46 mm | 38 mm | 48 mm | -6 mm |
June temperatures in Boulder have risen by about 2.7°C between 1981–1985 and 2021–2025.
June has ranged from a record low of 2.2°C (1998) to a record high of 39.9°C (2012).
Rainfall in June is about average for rainfall, averaging 47 mm, with a wettest year of 121 mm.
One of the best times to visit Boulder
June is one of the best times to visit Boulder. Expect days averaging 28.4°C and nights around 11.8°C (mean 20.1°C) — warmer than Boulder's yearly average — with moderate rainfall (47 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 30.1°C | 21.5°C | 12.8°C | 37.0°C | 6.5°C | 52 mm | 41% | 2.3 m/s | 7 |
| 2024 | 32.2°C | 23.5°C | 14.7°C | 37.1°C | 10.0°C | 22 mm | 38% | 2.4 m/s | 7 |
| 2023 🌧️ | 24.1°C | 17.5°C | 11.0°C | 32.9°C | 7.6°C | 121 mm | 59% | 1.9 m/s | 6.1 |
| 2022 | 30.0°C | 21.5°C | 13.0°C | 37.0°C | 3.7°C | 17 mm | 37% | 2.2 m/s | 7 |
| 2021 | 30.6°C | 22.2°C | 13.8°C | 38.1°C | 5.4°C | 37 mm | 39% | 2.3 m/s | 7.1 |
| 2020 | 30.2°C | 21.5°C | 12.8°C | 35.5°C | 2.4°C | 37 mm | 36% | 2.6 m/s | 6.9 |
| 2019 | 26.5°C | 18.7°C | 10.9°C | 34.9°C | 5.2°C | 64 mm | 49% | 2 m/s | 6.4 |
| 2018 | 31.5°C | 22.5°C | 13.6°C | 38.9°C | 6.4°C | 29 mm | 33% | 2.2 m/s | 7.2 |
| 2017 | 29.5°C | 21.0°C | 12.4°C | 35.6°C | 8.3°C | 14 mm | 42% | 2.2 m/s | 7.3 |
| 2016 | 30.6°C | 22.4°C | 14.2°C | 37.7°C | 8.5°C | 35 mm | 43% | 2.2 m/s | 7.3 |
| 2015 | 27.5°C | 20.3°C | 13.2°C | 34.8°C | 8.7°C | 68 mm | 56% | 1.9 m/s | 6.9 |
| 2014 | 28.4°C | 19.6°C | 10.8°C | 34.1°C | 4.7°C | 31 mm | 43% | 2.2 m/s | 7.4 |
| 2013 | 30.9°C | 21.8°C | 12.7°C | 36.5°C | 5.3°C | 20 mm | 34% | 2.2 m/s | 7.5 |
| 2012 🔥 | 33.3°C | 24.1°C | 14.9°C | 39.9°C | 7.7°C | 18 mm | 28% | 2.7 m/s | 7.5 |
| 2011 | 29.1°C | 20.3°C | 11.4°C | 36.4°C | 6.7°C | 39 mm | 40% | 2.2 m/s | 7.3 |
| 2010 | 28.5°C | 20.0°C | 11.5°C | 35.3°C | 4.4°C | 65 mm | 47% | 2 m/s | 6.9 |
| 2009 | 25.1°C | 17.6°C | 10.2°C | 31.2°C | 4.5°C | 92 mm | 55% | 1.8 m/s | 6.3 |
| 2008 | 28.6°C | 19.7°C | 10.8°C | 34.8°C | 4.3°C | 29 mm | 36% | 2.2 m/s | 7.3 |
| 2007 | 29.0°C | 20.6°C | 12.2°C | 37.0°C | 2.8°C | 17 mm | 38% | 2.5 m/s | 6.9 |
| 2006 | 31.8°C | 23.0°C | 14.1°C | 37.8°C | 10.3°C | 11 mm | 32% | 2.4 m/s | 7.4 |
| 2005 | 27.2°C | 19.1°C | 10.9°C | 33.4°C | 4.8°C | 93 mm | 46% | 2.3 m/s | 6.9 |
| 2004 | 26.4°C | 18.5°C | 10.7°C | 36.2°C | 5.8°C | 80 mm | 48% | 2.2 m/s | 6.1 |
| 2003 | 25.7°C | 17.7°C | 9.7°C | 32.7°C | 3.3°C | 53 mm | 51% | 2 m/s | 6.5 |
| 2002 | 32.0°C | 22.9°C | 13.8°C | 37.1°C | 6.6°C | 31 mm | 32% | 2.4 m/s | 7.4 |
| 2001 | 30.4°C | 21.4°C | 12.3°C | 37.0°C | 2.8°C | 24 mm | 36% | 2.2 m/s | 7.2 |
| 2000 | 29.0°C | 20.2°C | 11.3°C | 35.6°C | 4.2°C | 29 mm | 37% | 2.5 m/s | 7.2 |
| 1999 | 26.7°C | 18.4°C | 10.1°C | 32.9°C | 5.7°C | 43 mm | 47% | 2.3 m/s | 7 |
| 1998 | 26.1°C | 17.5°C | 9.0°C | 34.6°C | 2.2°C | 36 mm | 43% | 2.3 m/s | 7.1 |
| 1997 | 27.7°C | 19.9°C | 12.2°C | 34.3°C | 9.1°C | 74 mm | 50% | 2 m/s | 7.2 |
| 1996 | 28.1°C | 20.1°C | 12.0°C | 33.8°C | 5.5°C | 46 mm | 44% | 2.1 m/s | 7 |
| 1995 | 23.6°C | 16.4°C | 9.2°C | 30.8°C | 3.1°C | 90 mm | 57% | 2.1 m/s | 6.7 |
| 1994 | 31.1°C | 22.2°C | 13.4°C | 37.7°C | 8.0°C | 34 mm | 36% | 2.2 m/s | 7.2 |
| 1993 | 26.2°C | 18.1°C | 10.0°C | 34.5°C | 3.5°C | 57 mm | 45% | 2.1 m/s | 7 |
| 1992 | 26.2°C | 18.3°C | 10.5°C | 33.5°C | 3.6°C | 51 mm | 50% | 2.2 m/s | 5.9 |
| 1991 | 28.8°C | 20.5°C | 12.2°C | 36.6°C | 7.0°C | 52 mm | 43% | 2.5 m/s | 6.5 |
| 1990 | 31.6°C | 22.0°C | 12.5°C | 38.2°C | 4.0°C | 10 mm | 32% | 2.5 m/s | 7.2 |
| 1989 | 25.3°C | 17.6°C | 9.8°C | 36.9°C | 2.8°C | 59 mm | 47% | 2.1 m/s | 6.1 |
| 1988 | 29.7°C | 22.0°C | 14.4°C | 35.9°C | 5.2°C | 39 mm | 44% | 2.5 m/s | 6.6 |
| 1987 | 28.1°C | 20.2°C | 12.4°C | 32.8°C | 4.0°C | 65 mm | 45% | 2.1 m/s | 7.2 |
| 1986 | 28.4°C | 20.7°C | 12.9°C | 35.1°C | 6.4°C | 48 mm | 44% | 2.3 m/s | 6.4 |
| 1985 | 28.4°C | 19.6°C | 10.8°C | 36.2°C | 5.0°C | 44 mm | 37% | 2.2 m/s | 6.8 |
| 1984 | 26.6°C | 18.6°C | 10.6°C | 34.2°C | 3.8°C | 55 mm | 46% | 2.2 m/s | 6.3 |
| 1983 ❄️ | 23.8°C | 16.3°C | 8.8°C | 33.1°C | 2.3°C | 79 mm | 55% | 2.1 m/s | — |
| 1982 | 24.4°C | 16.8°C | 9.3°C | 34.0°C | 4.1°C | 62 mm | 50% | 2.1 m/s | — |
| 1981 | 29.9°C | 21.2°C | 12.5°C | 35.9°C | 4.1°C | 36 mm | 41% | 2.3 m/s | — |
Actual recorded June data for each year, 1981–2025 — sourced from NASA POWER.
The average high in June is around 28.4°C with lows near 11.8°C (mean 20.1°C), based on 45 years of NASA POWER data.
June averages 47 mm of rainfall in Boulder, about average for rainfall. The wettest on record was 121 mm in 2023.
The hottest June reached 39.9°C in 2012. The coldest dipped to 2.2°C in 1998.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average June temperatures have risen by about 2.7°C. Daytime highs moved from 26.6°C to 29.4°C and overnight lows from 10.4°C to 13.1°C over the same span.
June is one of the warmer months of the year in Boulder and about average for rainfall, so plan for around 28.4°C daytime highs and 11.8°C at night.
Not quite — June is the 10th coolest month in Boulder, averaging 20.1°C.
For June in Boulder, pack light layers you can adjust through the day, with typical highs of 28.4°C and lows of 11.8°C.
Relative humidity in June averages 43% — relatively dry.
Average wind speed in June is 2.2 m/s. The windiest June on record averaged 2.7 m/s (2012).
The wettest June on record was 2023 with 121 mm. On average, June sees 47 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 Boulder behaves each June, 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 June specifically, along with year-by-year records and how the month has changed over the decades.
