April is one of the cooler months of the year in Flagstaff, with average highs near 17.9°C and lows around 1.7°C (mean 9.8°C). It is one of the drier months, averaging 21 mm of rainfall and 44% relative humidity across the period.
April is one of the cooler months of the year in Flagstaff. Across 45 years of records, the warmest April in Flagstaff was 1989 — when the month averaged 13.4°C — while the coldest was 1983 at 5.4°C. Typical April days reach 17.9°C with nights near 1.7°C. The long-term trend is warming, about 0.4°C per decade.
April is one of the drier months in Flagstaff, averaging 21 mm of rainfall. The wettest April on record was 1988 with 84 mm, while the driest were 1989 and 1991 at 0 mm.
Relative humidity in Flagstaff during April averages 44%. The most humid April was 1983 at 60%, and the least humid was 2018 at 29%.
April receives about 6.9 kWh/m²/day of solar energy in Flagstaff. The sunniest April was 2008 at 7.7 kWh/m²/day, and the cloudiest were 1985 and 1990 at 6.3.
Average wind speed in Flagstaff during April is 2.9 m/s. The windiest April was 2011 at 3.7 m/s, while the calmest was 1987 at 2.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.5°C | 8.8°C | 9.9°C | 10.4°C | 10.7°C | +1.2°C |
| Avg High | 17.6°C | 16.6°C | 18.1°C | 18.5°C | 19.0°C | +1.4°C |
| Avg Low | 1.5°C | 0.9°C | 1.7°C | 2.3°C | 2.4°C | +0.9°C |
| Avg Rain | 30 mm | 30 mm | 17 mm | 12 mm | 13 mm | -18 mm |
April temperatures in Flagstaff have risen by about 1.9°C between 1981–1985 and 2021–2025.
April has ranged from a record low of -11.3°C (1999) to a record high of 29.9°C (2020).
Rainfall in April is one of the drier months, averaging 21 mm, with a wettest year of 84 mm.
A good time to visit Flagstaff
April is a good time to visit Flagstaff, with days averaging 17.9°C and nights around 1.7°C (mean 9.8°C, cooler than Flagstaff's yearly average) and low rainfall. June 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 | 18.3°C | 10.2°C | 2.1°C | 28.2°C | -4.8°C | 28 mm | 40% | 2.6 m/s | 6.8 |
| 2024 | 18.5°C | 10.4°C | 2.2°C | 25.9°C | -3.5°C | 16 mm | 44% | 2.7 m/s | 7.1 |
| 2023 | 18.4°C | 9.8°C | 1.2°C | 27.6°C | -6.6°C | 1 mm | 45% | 2.8 m/s | 7.3 |
| 2022 | 20.0°C | 11.3°C | 2.6°C | 25.8°C | -5.6°C | 1 mm | 31% | 3.2 m/s | 7.5 |
| 2021 | 20.3°C | 12.0°C | 3.7°C | 26.6°C | -3.8°C | 8 mm | 33% | 3 m/s | 7.4 |
| 2020 | 18.6°C | 10.7°C | 2.7°C | 29.9°C | -4.5°C | 23 mm | 49% | 2.8 m/s | 7.1 |
| 2019 | 18.8°C | 11.1°C | 3.4°C | 26.2°C | -3.2°C | 8 mm | 48% | 2.8 m/s | 6.7 |
| 2018 | 21.1°C | 12.7°C | 4.3°C | 26.7°C | -3.7°C | 3 mm | 29% | 3.2 m/s | 7 |
| 2017 | 19.1°C | 10.7°C | 2.2°C | 23.5°C | -4.4°C | 4 mm | 42% | 2.9 m/s | 7.1 |
| 2016 | 17.4°C | 9.6°C | 1.9°C | 25.4°C | -2.6°C | 25 mm | 47% | 2.7 m/s | 6.5 |
| 2015 | 17.9°C | 9.7°C | 1.5°C | 25.8°C | -5.9°C | 16 mm | 41% | 2.7 m/s | 7 |
| 2014 | 18.1°C | 10.0°C | 2.0°C | 24.6°C | -5.6°C | 14 mm | 38% | 3 m/s | 6.8 |
| 2013 | 18.7°C | 10.4°C | 2.1°C | 28.0°C | -6.6°C | 8 mm | 37% | 3.2 m/s | 7.2 |
| 2012 | 19.7°C | 11.6°C | 3.6°C | 29.5°C | -4.2°C | 19 mm | 37% | 2.8 m/s | 7 |
| 2011 | 17.8°C | 9.6°C | 1.4°C | 25.1°C | -8.6°C | 16 mm | 41% | 3.7 m/s | 7.2 |
| 2010 | 16.3°C | 8.3°C | 0.3°C | 23.1°C | -4.9°C | 13 mm | 47% | 3.2 m/s | 7 |
| 2009 | 16.9°C | 8.6°C | 0.3°C | 25.7°C | -5.8°C | 8 mm | 41% | 3.2 m/s | 7.2 |
| 2008 | 17.4°C | 8.7°C | -0.1°C | 24.8°C | -5.3°C | 1 mm | 35% | 3.3 m/s | 7.7 |
| 2007 | 18.9°C | 10.5°C | 2.2°C | 26.5°C | -4.6°C | 9 mm | 40% | 3 m/s | 6.8 |
| 2006 | 19.1°C | 10.4°C | 1.7°C | 25.6°C | -3.3°C | 15 mm | 38% | 3 m/s | 7.3 |
| 2005 | 16.7°C | 9.0°C | 1.3°C | 22.9°C | -5.1°C | 38 mm | 51% | 3 m/s | 7.1 |
| 2004 | 17.0°C | 9.4°C | 1.8°C | 25.5°C | -2.3°C | 30 mm | 46% | 2.8 m/s | 6.6 |
| 2003 | 16.4°C | 8.3°C | 0.2°C | 22.6°C | -5.6°C | 8 mm | 42% | 3.5 m/s | 7 |
| 2002 | 20.9°C | 12.7°C | 4.4°C | 27.2°C | -2.9°C | 12 mm | 33% | 3.3 m/s | 7.1 |
| 2001 | 17.4°C | 9.5°C | 1.6°C | 27.0°C | -5.6°C | 36 mm | 50% | 3.3 m/s | 6.7 |
| 2000 | 20.6°C | 11.9°C | 3.1°C | 29.1°C | -3.1°C | 14 mm | 39% | 2.7 m/s | 7.5 |
| 1999 | 13.4°C | 5.7°C | -1.9°C | 24.8°C | -11.3°C | 65 mm | 53% | 3.2 m/s | 6.6 |
| 1998 | 13.5°C | 6.3°C | -0.9°C | 23.8°C | -6.0°C | 46 mm | 58% | 2.8 m/s | 7 |
| 1997 | 15.8°C | 8.2°C | 0.7°C | 23.7°C | -6.3°C | 44 mm | 49% | 2.9 m/s | 6.5 |
| 1996 | 19.4°C | 10.4°C | 1.3°C | 28.0°C | -5.0°C | 2 mm | 33% | 2.7 m/s | 7 |
| 1995 | 14.8°C | 7.4°C | 0.0°C | 22.5°C | -4.7°C | 40 mm | 53% | 3.1 m/s | 6.7 |
| 1994 | 16.9°C | 9.3°C | 1.7°C | 26.3°C | -4.4°C | 48 mm | 49% | 2.8 m/s | 6.4 |
| 1993 | 17.4°C | 9.3°C | 1.3°C | 23.4°C | -5.7°C | 7 mm | 53% | 2.7 m/s | 7 |
| 1992 | 20.3°C | 12.0°C | 3.7°C | 27.5°C | -2.4°C | 11 mm | 51% | 2.3 m/s | 7.1 |
| 1991 | 16.8°C | 8.2°C | -0.4°C | 23.6°C | -6.4°C | 0 mm | 44% | 3 m/s | 7.2 |
| 1990 | 18.1°C | 10.7°C | 3.3°C | 25.6°C | -1.6°C | 35 mm | 48% | 2.7 m/s | 6.3 |
| 1989 🔥 | 22.2°C | 13.4°C | 4.6°C | 27.9°C | -2.0°C | 0 mm | 34% | 2.7 m/s | 7.2 |
| 1988 🌧️ | 16.8°C | 9.0°C | 1.2°C | 24.3°C | -5.2°C | 84 mm | 53% | 2.7 m/s | 6.6 |
| 1987 | 18.5°C | 10.3°C | 2.1°C | 24.8°C | -5.0°C | 11 mm | 49% | 2.2 m/s | 6.7 |
| 1986 | 17.1°C | 9.1°C | 1.0°C | 23.4°C | -4.6°C | 15 mm | 47% | 3.2 m/s | 6.7 |
| 1985 | 18.4°C | 10.6°C | 2.8°C | 24.1°C | -5.4°C | 59 mm | 54% | 2.5 m/s | 6.3 |
| 1984 | 15.5°C | 7.4°C | -0.6°C | 25.1°C | -5.0°C | 16 mm | 45% | 3 m/s | 6.4 |
| 1983 ❄️ | 12.3°C | 5.4°C | -1.4°C | 20.5°C | -6.1°C | 50 mm | 60% | 3 m/s | — |
| 1982 | 17.7°C | 9.3°C | 0.9°C | 25.1°C | -7.0°C | 9 mm | 46% | 3.1 m/s | — |
| 1981 | 19.9°C | 11.3°C | 2.8°C | 26.9°C | -5.7°C | 30 mm | 43% | 2.8 m/s | — |
Actual recorded April data for each year, 1981–2025 — sourced from NASA POWER.
The average high in April is around 17.9°C with lows near 1.7°C (mean 9.8°C), based on 45 years of NASA POWER data.
April averages 21 mm of rainfall in Flagstaff, one of the drier months. The wettest on record was 84 mm in 1988.
The hottest April reached 29.9°C in 2020. The coldest dipped to -11.3°C in 1999.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average April temperatures have risen by about 1.9°C. Daytime highs moved from 16.8°C to 19.1°C and overnight lows from 0.9°C to 2.4°C over the same span.
April is one of the cooler months of the year in Flagstaff and one of the drier months, so plan for around 17.9°C daytime highs and 1.7°C at night.
Not quite — April is the 6th coolest month in Flagstaff, averaging 9.8°C.
For April in Flagstaff, pack warm layers and a jacket for chilly mornings, with typical highs of 17.9°C and lows of 1.7°C.
Relative humidity in April averages 44% — relatively dry.
Average wind speed in April is 2.9 m/s. The windiest April on record averaged 3.7 m/s (2011).
The wettest April on record was 1988 with 84 mm. On average, April sees 21 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 Flagstaff 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.
