July is one of the warmer months of the year in Boston, with average highs near 20.8°C and lows around 12.4°C (mean 16.6°C). It is about average for rainfall, averaging 59 mm of rainfall and 80% relative humidity across the period.
July is one of the warmer months of the year in Boston. Across 45 years of records, the warmest Julys in Boston were 2006 and 2018 — when the month averaged 18.8°C — while the coldest was 2000 at 14.6°C. Typical July days reach 20.8°C with nights near 12.4°C. The long-term trend is warming, about 0.3°C per decade.
July is about average for rainfall in Boston, averaging 59 mm of rainfall. The wettest July on record was 2012 with 104 mm, while the driest was 2022 at 22 mm.
Relative humidity in Boston during July averages 80%. The most humid July was 2000 at 83%, and the least humid was 1990 at 75%.
July receives about 5 kWh/m²/day of solar energy in Boston. The sunniest July was 2006 at 6 kWh/m²/day, and the cloudiest was 1987 at 4.3.
Average wind speed in Boston during July is 3.1 m/s. The windiest July was 1988 at 4.2 m/s, while the calmest was 1983 at 2.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 16.0°C | 16.7°C | 16.4°C | 16.9°C | 17.1°C | +1.1°C |
| Avg High | 20.3°C | 21.1°C | 20.4°C | 21.2°C | 21.3°C | +1°C |
| Avg Low | 11.8°C | 12.2°C | 12.4°C | 12.7°C | 12.9°C | +1.1°C |
| Avg Rain | 51 mm | 45 mm | 73 mm | 63 mm | 66 mm | +15 mm |
July temperatures in Boston have risen by about 1.3°C between 1981–1985 and 2021–2025.
July has ranged from a record low of 6.6°C (1996) to a record high of 31.6°C (2022).
Rainfall in July is about average for rainfall, averaging 59 mm, with a wettest year of 104 mm.
One of the best times to visit Boston
July is one of the best times to visit Boston. Expect days averaging 20.8°C and nights around 12.4°C (mean 16.6°C) — warmer than Boston's yearly average — with moderate rainfall (59 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 | 22.3°C | 18.0°C | 13.6°C | 27.7°C | 10.0°C | 66 mm | 79% | 2.9 m/s | 5 |
| 2024 | 20.7°C | 16.5°C | 12.3°C | 27.2°C | 8.8°C | 80 mm | 81% | 3 m/s | 4.9 |
| 2023 | 20.6°C | 16.7°C | 12.7°C | 25.4°C | 10.1°C | 89 mm | 78% | 3.8 m/s | 4.4 |
| 2022 | 22.7°C | 18.1°C | 13.4°C | 31.6°C | 10.0°C | 22 mm | 76% | 2.9 m/s | 5.2 |
| 2021 | 21.8°C | 17.6°C | 13.5°C | 27.0°C | 9.9°C | 62 mm | 82% | 2.6 m/s | 5.1 |
| 2020 | 19.9°C | 15.9°C | 11.8°C | 27.6°C | 7.9°C | 76 mm | 80% | 3.5 m/s | 4.8 |
| 2019 | 22.1°C | 17.8°C | 13.5°C | 30.5°C | 9.8°C | 76 mm | 79% | 2.9 m/s | 4.9 |
| 2018 | 23.5°C | 18.8°C | 14.0°C | 28.8°C | 10.5°C | 32 mm | 78% | 2.6 m/s | 5.9 |
| 2017 | 20.7°C | 16.6°C | 12.5°C | 25.6°C | 10.7°C | 78 mm | 80% | 3.3 m/s | 5 |
| 2016 | 21.0°C | 16.8°C | 12.6°C | 27.3°C | 8.7°C | 37 mm | 80% | 3.1 m/s | 5.1 |
| 2015 | 20.4°C | 16.1°C | 11.8°C | 27.9°C | 7.1°C | 96 mm | 78% | 3.3 m/s | 5 |
| 2014 | 21.8°C | 17.6°C | 13.4°C | 25.4°C | 8.5°C | 52 mm | 80% | 2.9 m/s | 5.6 |
| 2013 | 22.2°C | 17.6°C | 13.1°C | 26.1°C | 8.8°C | 64 mm | 80% | 2.5 m/s | 5.7 |
| 2012 🌧️ | 19.6°C | 15.6°C | 11.6°C | 26.2°C | 8.6°C | 104 mm | 80% | 2.9 m/s | 4.6 |
| 2011 | 19.5°C | 15.3°C | 11.1°C | 24.1°C | 8.4°C | 53 mm | 77% | 3.1 m/s | 4.6 |
| 2010 | 21.3°C | 17.2°C | 13.2°C | 25.2°C | 9.6°C | 34 mm | 79% | 3.2 m/s | 4.9 |
| 2009 | 20.2°C | 16.2°C | 12.1°C | 24.8°C | 8.7°C | 85 mm | 81% | 3.5 m/s | 5 |
| 2008 | 20.7°C | 16.4°C | 12.2°C | 25.8°C | 8.7°C | 59 mm | 81% | 3.4 m/s | 5.1 |
| 2007 | 19.0°C | 15.5°C | 11.9°C | 21.6°C | 8.9°C | 95 mm | 82% | 3.6 m/s | 4.4 |
| 2006 🔥 | 23.5°C | 18.8°C | 14.2°C | 27.1°C | 9.9°C | 43 mm | 79% | 2.6 m/s | 6 |
| 2005 | 20.0°C | 16.1°C | 12.3°C | 24.7°C | 9.4°C | 83 mm | 82% | 3.2 m/s | 4.5 |
| 2004 | 19.9°C | 15.9°C | 11.9°C | 24.4°C | 8.7°C | 82 mm | 81% | 2.8 m/s | 4.6 |
| 2003 | 21.3°C | 17.4°C | 13.4°C | 24.9°C | 10.6°C | 61 mm | 82% | 3.1 m/s | 4.8 |
| 2002 | 20.1°C | 16.1°C | 12.1°C | 26.3°C | 9.0°C | 96 mm | 82% | 2.7 m/s | 4.6 |
| 2001 | 21.0°C | 16.9°C | 12.8°C | 26.3°C | 7.6°C | 74 mm | 80% | 3.1 m/s | 4.7 |
| 2000 ❄️ | 18.2°C | 14.6°C | 10.9°C | 21.8°C | 8.0°C | 54 mm | 83% | 2.8 m/s | 4.6 |
| 1999 | 21.3°C | 16.8°C | 12.3°C | 24.9°C | 9.4°C | 27 mm | 80% | 3.1 m/s | 5.7 |
| 1998 | 19.3°C | 15.3°C | 11.3°C | 23.9°C | 9.0°C | 35 mm | 80% | 3.7 m/s | 4.6 |
| 1997 | 20.6°C | 16.3°C | 12.0°C | 24.2°C | 9.5°C | 52 mm | 81% | 2.9 m/s | 5.1 |
| 1996 | 20.9°C | 16.2°C | 11.4°C | 27.8°C | 6.6°C | 42 mm | 78% | 3 m/s | 5.3 |
| 1995 | 22.3°C | 17.8°C | 13.4°C | 26.8°C | 8.9°C | 36 mm | 80% | 2.9 m/s | 5.5 |
| 1994 | 22.3°C | 17.6°C | 13.0°C | 27.5°C | 9.9°C | 39 mm | 80% | 2.6 m/s | 5.6 |
| 1993 | 19.4°C | 15.3°C | 11.2°C | 23.4°C | 7.1°C | 67 mm | 79% | 3.7 m/s | 5 |
| 1992 | 21.1°C | 16.9°C | 12.7°C | 25.4°C | 10.2°C | 86 mm | 76% | 3.2 m/s | 4.5 |
| 1991 | 22.4°C | 17.9°C | 13.4°C | 26.4°C | 10.4°C | 36 mm | 77% | 3.3 m/s | 5 |
| 1990 | 21.2°C | 16.4°C | 11.6°C | 27.6°C | 7.5°C | 33 mm | 75% | 3.4 m/s | 5.5 |
| 1989 | 21.7°C | 17.2°C | 12.7°C | 27.8°C | 9.2°C | 50 mm | 79% | 2.9 m/s | 5.3 |
| 1988 | 18.9°C | 15.1°C | 11.4°C | 23.5°C | 8.6°C | 93 mm | 82% | 4.2 m/s | 4.4 |
| 1987 | 19.7°C | 15.8°C | 12.0°C | 26.0°C | 8.8°C | 69 mm | 81% | 3.2 m/s | 4.3 |
| 1986 | 19.9°C | 15.7°C | 11.5°C | 25.8°C | 8.2°C | 48 mm | 80% | 3.1 m/s | 4.4 |
| 1985 | 20.1°C | 15.9°C | 11.7°C | 23.7°C | 8.7°C | 54 mm | 81% | 3.3 m/s | 4.8 |
| 1984 | 19.8°C | 15.3°C | 10.9°C | 24.6°C | 7.1°C | 26 mm | 81% | 2.7 m/s | 5.2 |
| 1983 | 22.7°C | 17.8°C | 13.0°C | 26.9°C | 7.3°C | 52 mm | 82% | 2.1 m/s | — |
| 1982 | 20.1°C | 15.9°C | 11.7°C | 25.7°C | 8.4°C | 33 mm | 82% | 3 m/s | — |
| 1981 | 19.4°C | 15.4°C | 11.4°C | 23.6°C | 9.0°C | 36 mm | 82% | 3 m/s | — |
Actual recorded July data for each year, 1981–2025 — sourced from NASA POWER.
The average high in July is around 20.8°C with lows near 12.4°C (mean 16.6°C), based on 45 years of NASA POWER data.
July averages 59 mm of rainfall in Boston, about average for rainfall. The wettest on record was 104 mm in 2012.
The hottest July reached 31.6°C in 2022. The coldest dipped to 6.6°C in 1996.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average July temperatures have risen by about 1.3°C. Daytime highs moved from 20.4°C to 21.6°C and overnight lows from 11.7°C to 13.1°C over the same span.
July is one of the warmer months of the year in Boston and about average for rainfall, so plan for around 20.8°C daytime highs and 12.4°C at night.
Not quite — July is the 11th coolest month in Boston, averaging 16.6°C.
For July in Boston, pack light layers you can adjust through the day, with typical highs of 20.8°C and lows of 12.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in July averages 80% — quite humid.
Average wind speed in July is 3.1 m/s. The windiest July on record averaged 4.2 m/s (1988).
The wettest July on record was 2012 with 104 mm. On average, July sees 59 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 Boston behaves each July, 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 July specifically, along with year-by-year records and how the month has changed over the decades.
