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Mount Vernon climate
Typical historical weather for Mount Vernon, United States, averaged across 10 years of hourly climate data. Pick a date for a specific day.
Want today's actual conditions instead? See the current forecast for Mount Vernon. Planning a garden? See the gardening & growing season planner. Or browse the 365-day climate calendar.
Annual average
14.3°C
across all months
Warmest month
29.7°C
Jul average high
Coolest month
-0.7°C
Jan average low
Annual rainfall
1320mm
total per year
Mount Vernon is typically hottest in July and coolest in January, a swing of about 30.4°C across the year. About 31% of annual rainfall falls in the three wettest months (July is typically wettest, November driest).
Monthly averages
Average daily high/low temperature (band) and monthly rainfall (bars).
| Month | Avg high | Avg low | Rainfall | Wet days | Humidity | Wind | Cloud | Solar |
|---|---|---|---|---|---|---|---|---|
| Jan | 5.1°C · record 10.5–16.9°C | -0.7°C · record -13.6–-1.2°C | 92mm | 10 | 67% | 4.2 m/s | 57% | 2.2 kWh/m² |
| Feb | 7.5°C · record 11.6–20.6°C | 0.9°C · record -11.3–-3°C | 105mm | 11 | 67% | 4 m/s | 62% | 2.9 kWh/m² |
| Mar | 11.6°C · record 17.4–23.5°C | 4.2°C · record -6.7–-0.5°C | 100mm | 10 | 63% | 4.3 m/s | 56% | 4.2 kWh/m² |
| Apr | 16.9°C · record 21.4–26.8°C | 9.4°C · record -0.7–5°C | 101mm | 10 | 65% | 4.1 m/s | 61% | 5.1 kWh/m² |
| May | 21.5°C · record 24.8–31.3°C | 14.6°C · record 3.2–10.9°C | 132mm | 14 | 72% | 3.5 m/s | 66% | 5.3 kWh/m² |
| Jun | 26.8°C · record 29.7–34.3°C | 19.9°C · record 11.1–15.1°C | 104mm | 12 | 70% | 3.3 m/s | 59% | 6.2 kWh/m² |
| Jul | 29.7°C · record 31.9–35.3°C | 23.4°C · record 17.2–21.9°C | 154mm | 15 | 73% | 2.7 m/s | 57% | 6 kWh/m² |
| Aug | 28.2°C · record 30.7–34.3°C | 22.1°C · record 14–18.9°C | 116mm | 13 | 74% | 2.8 m/s | 55% | 5.3 kWh/m² |
| Sep | 25.1°C · record 28–33.5°C | 18.7°C · record 9.5–15.2°C | 117mm | 11 | 74% | 3.2 m/s | 56% | 4.1 kWh/m² |
| Oct | 19.5°C · record 22.8–32.4°C | 12.6°C · record 3.7–9.5°C | 101mm | 9 | 73% | 3.7 m/s | 49% | 3.3 kWh/m² |
| Nov | 12.7°C · record 18.6–24°C | 5.6°C · record -3.8–0.3°C | 79mm | 8 | 67% | 3.9 m/s | 48% | 2.6 kWh/m² |
| Dec | 7.3°C · record 12–17.4°C | 1.3°C · record -13–-1.1°C | 120mm | 10 | 69% | 3.8 m/s | 60% | 1.9 kWh/m² |
"Avg high"/"Avg low" is the mean daily high/low for that month, averaged across every year on file. The "record" figure alongside it is a different statistic — the single hottest (or coldest) hour ever recorded during that month across all years — so it can sit above or below the average and does not describe the average's year-to-year spread. A "wet day" is any day with at least 1.0mm of rain.
Year to year
Annual average temperature, 2016–2025.
Across these 10 years, the annual average has moved by about +0.03°C per decade. That’s a short window for a reliable long-term climate trend — treat it as indicative, not definitive.
Annual rainfall has moved by about -179.57mm per decade over the same period.
2025 (the most recent year on file) averaged 13.6893829067004°C, below the 9-year baseline of 14.37°C by 2.05 standard deviations — a genuinely unusual year.
Typical extremes per year
Rainy days
134.3 days
≥1.0mm rain
Heavy rain days
16.3 days
≥20mm rain
Extreme heat days
0 days
daily high ≥40°C
Frost days
46 days
daily low ≤0°C
Averaged across 10 years on file. Thresholds match PastClimate's data pipeline definitions — see data & sources.
Records on file
Ranked across 10 years of data currently on file (2016–2025).
Hottest day
35.3°C
16 July 2024
2024 was 0.98 SD above the 9-year average that year
Coldest day
-13.6°C
31 January 2019
2019 was 0.13 SD above the 9-year average that year
Wettest day
82.2mm
21 July 2018
2018 was 1.34 SD below the 9-year average that year
Windiest day
11.7m/s
2 March 2018
2018 was 1.34 SD below the 9-year average that year
See the detail: Mount Vernon on 21 July 2018.
Nearby cities
Baltimore
Same ERA5 grid cell
Glen Burnie
Same ERA5 grid cell
Dundalk
Same ERA5 grid cell
Essex
Same ERA5 grid cell
Middle River
Same ERA5 grid cell
Pasadena
Same ERA5 grid cell
Want a side-by-side view instead? Compare Mount Vernon with another city.
Frequently asked questions about Mount Vernon's climate
What is the hottest month in Mount Vernon?
July is typically the warmest month in Mount Vernon, with an average high of 29.7°C. January is typically the coolest, averaging -0.7°C overnight.
How much does it rain in Mount Vernon?
Mount Vernon gets about 1320mm of rain a year on average, with roughly 31% of it falling in the three wettest months (July is typically the wettest, November the driest).
How many extremely hot or cold days does Mount Vernon have?
On average, Mount Vernon sees about 0 day(s) a year at or above 40°C and about 46 day(s) at or below 0°C, based on 10 years of data.
Is Mount Vernon getting warmer?
Across the 10 years on file (2016–2025), the annual average temperature has moved by about +0.03°C per decade. That's a short window for a reliable long-term climate trend — treat it as indicative, not definitive.
What is the hottest day on record for Mount Vernon?
The hottest day on file is 16 July 2024 at 35.3°C, out of 10 year(s) searched.
Data & provenance
↓ Download monthly CSVData source & coverage — ERA5 reanalysis, 2016–2025 (10 years)details
- Source
- ERA5 reanalysis, accessed via the Copernicus Climate Change Service (C3S) Climate Data Store
- Data type
- Reanalysis — a physically consistent reconstruction combining a forecast model with historical observations, not a live station reading or a forecast
- Coverage
- 2016–2025 (10 years) for United States
- Location
- Mount Vernon — 39.250°, -76.500°, ERA5 grid cell center, 11.3 km from requested point
- Time zone
- America/New_York
- What's shown here
- Monthly and annual averages, and dated extreme-value records, derived from an hourly base record.
- Spatial resolution
- 0.25° (~25 km) distributed grid — ERA5's native model resolution is finer; this is the publicly distributed regridded product
- Version / refreshed
- Methodology v2026.07 · data last refreshed December 31, 2025
- Limitations
- A model reconstruction, not a station observation — hyper-local extremes (a single storm cell, an urban heat pocket) can differ from a nearby gauge. See the full methodology.
- Attribution
- Generated using Copernicus Climate Change Service information
Cite this data
PastClimate (2026-07-18). Historical climate data for Mount Vernon, United States (39.25°N, 76.50°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Mount Vernon, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 18, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Mount Vernon, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 18, 2026, www.pastclimate.com.
@misc{pastclimate,
author = {PastClimate},
title = {Historical climate data for Mount Vernon, United States},
year = {2026},
note = {Derived from ERA5 (Hersbach et al., 2023), Copernicus Climate Change Service. Accessed 2026-07-18},
url = {https://www.pastclimate.com/}
}Notice something wrong with this data? Report a data issue.