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Williamstown climate
Typical historical weather for Williamstown, United States, averaged across 10 years of hourly climate data. Pick a date for a specific day.
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Annual average
13.8°C
across all months
Warmest month
30°C
Jul average high
Coolest month
-2.6°C
Jan average low
Annual rainfall
1287mm
total per year
Williamstown is typically hottest in July and coolest in January, a swing of about 32.6°C across the year. About 30% of annual rainfall falls in the three wettest months (July is typically wettest, October 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 | 4.7°C · record 13.5–20.7°C | -2.6°C · record -22.3–-6°C | 95mm | 11 | 72% | 3.2 m/s | 70% | 2.1 kWh/m² |
| Feb | 9°C · record 17.3–26.2°C | -0.4°C · record -16.7–-8.3°C | 118mm | 12 | 68% | 3.3 m/s | 68% | 2.9 kWh/m² |
| Mar | 14°C · record 16.9–27.1°C | 3.6°C · record -12.4–-2.8°C | 123mm | 13 | 62% | 3.4 m/s | 64% | 4.1 kWh/m² |
| Apr | 18.8°C · record 26.3–29.4°C | 8.1°C · record -3.1–1.5°C | 126mm | 12 | 63% | 3.3 m/s | 64% | 5.1 kWh/m² |
| May | 23.6°C · record 28.7–32°C | 14.1°C · record 0–8.9°C | 127mm | 16 | 71% | 2.7 m/s | 66% | 5.5 kWh/m² |
| Jun | 28.3°C · record 31.8–36.2°C | 18.5°C · record 8.6–13.5°C | 123mm | 12 | 70% | 2.5 m/s | 56% | 6.3 kWh/m² |
| Jul | 30°C · record 32.3–35.2°C | 20.9°C · record 13.9–19.3°C | 135mm | 14 | 74% | 2.1 m/s | 56% | 6.1 kWh/m² |
| Aug | 29.1°C · record 32.5–35.8°C | 19.5°C · record 9.7–15.5°C | 87mm | 12 | 74% | 2.1 m/s | 52% | 5.6 kWh/m² |
| Sep | 27°C · record 30.7–35.3°C | 16°C · record 5.8–12°C | 87mm | 8 | 72% | 2.3 m/s | 45% | 4.7 kWh/m² |
| Oct | 20.6°C · record 25.2–34.2°C | 9.8°C · record -0.9–4.7°C | 82mm | 9 | 71% | 2.8 m/s | 50% | 3.5 kWh/m² |
| Nov | 12.7°C · record 17.6–27.5°C | 3.2°C · record -10.7–-1.6°C | 84mm | 10 | 69% | 3 m/s | 56% | 2.4 kWh/m² |
| Dec | 7.8°C · record 15.8–21.8°C | 0°C · record -22–-4.4°C | 99mm | 12 | 72% | 3.1 m/s | 70% | 1.8 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 +0.09°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 -146.19mm per decade over the same period.
2025 (the most recent year on file) averaged 13.414524038306132°C, below the 9-year baseline of 13.86°C by 1.29 standard deviations.
Typical extremes per year
Rainy days
139.7 days
≥1.0mm rain
Heavy rain days
15.4 days
≥20mm rain
Extreme heat days
0 days
daily high ≥40°C
Frost days
70.6 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
36.2°C
22 June 2022
2022 was 1.29 SD below the 9-year average that year
Coldest day
-22.3°C
21 January 2019
2019 was 0.2 SD below the 9-year average that year
Wettest day
73.2mm
9 June 2021
2021 was 0.29 SD below the 9-year average that year
Windiest day
7.6m/s
24 February 2019
2019 was 0.2 SD below the 9-year average that year
See the detail: Williamstown on 9 June 2021.
Nearby cities
Crittenden
Same ERA5 grid cell
Dry Ridge
Same ERA5 grid cell
Falmouth
21.7 km away
Covington
27.8 km away
Independence
27.8 km away
Erlanger
27.8 km away
Want a side-by-side view instead? Compare Williamstown with another city.
Frequently asked questions about Williamstown's climate
What is the hottest month in Williamstown?
July is typically the warmest month in Williamstown, with an average high of 30°C. January is typically the coolest, averaging -2.6°C overnight.
How much does it rain in Williamstown?
Williamstown gets about 1287mm of rain a year on average, with roughly 30% of it falling in the three wettest months (July is typically the wettest, October the driest).
How many extremely hot or cold days does Williamstown have?
On average, Williamstown sees about 0 day(s) a year at or above 40°C and about 70.6 day(s) at or below 0°C, based on 10 years of data.
Is Williamstown getting warmer?
Across the 10 years on file (2016–2025), the annual average temperature has moved by about +0.09°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 Williamstown?
The hottest day on file is 22 June 2022 at 36.2°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
- Williamstown — 38.750°, -84.500°, ERA5 grid cell center, 13.5 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 Williamstown, United States (38.75°N, 84.50°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Williamstown, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 18, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Williamstown, 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 Williamstown, 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.