Potomac
United States · 7 July 2020
Average
26.2°C
low 21.7°C · high 31.1°C
Rainfall
1.3mm
rain recorded
Wind
2.1m/s
daily average
Humidity
75.5%
daily average
Cloud
73%
cover
Pressure
1017hPa
daily average
The temperature ranged from 21.7°C around 05:00 to 31.1°C around 15:00. Rain was recorded across 4 hours, from around 01:00 to 18:00 (1.3mm total).
How unusual was this day?
Compared against the same 135 calendar days (±7 days) across the other 9 years on file.
High temperature
36th percentile
Low temperature
41th percentile
Rainfall
54th percentile
Wind
46th percentile
A percentile of 100 means this was the hottest/wettest/windiest of the comparable days on file; 50 is right in the middle. This window's average temperature was 26.5°C, versus 26.2°C on this specific day.
Sun & daylight
Sunrise
05:50
Sunset
20:37
Day length
14h 47m
Hour by hour
Temperature (line) and hourly rainfall (bars), local time — America/New_York.
Cumulative rainfall through the day.
| Local time | UTC | Temp | Feels | Rain mm | Wind m/s | Dir | Humidity % | Pressure hPa |
|---|---|---|---|---|---|---|---|---|
| 00:00 | 04:00 | 22.9°C | 24.6°C | 0 | 3.7 | ESE | 90 | 1019 |
| 01:00 | 05:00 | 22.7°C | 24.6°C | 0.14 | 3.3 | ESE | 90 | 1018 |
| 02:00 | 06:00 | 22.4°C | 24.5°C | 0.06 | 2.7 | SE | 89 | 1018 |
| 03:00 | 07:00 | 22.5°C | 25°C | 0.15 | 1.9 | SSE | 88 | 1017 |
| 04:00 | 08:00 | 22°C | 24.8°C | 0 | 1.4 | S | 89 | 1017 |
| 05:00 | 09:00 | 21.7°C | 24.8°C | 0 | 1.1 | SE | 91 | 1017 |
| 06:00 | 10:00 | 23.2°C | 27.2°C | 0.03 | 0.8 | ENE | 92 | 1018 |
| 07:00 | 11:00 | 23.5°C | 27.1°C | 0.02 | 1.5 | ENE | 90 | 1018 |
| 08:00 | 12:00 | 24°C | 27.5°C | 0.1 | 1.4 | ENE | 86 | 1018 |
| 09:00 | 13:00 | 24.5°C | 28.3°C | 0.02 | 1.6 | E | 89 | 1018 |
| 10:00 | 14:00 | 25.6°C | 28.9°C | 0.02 | 1.9 | E | 79 | 1018 |
| 11:00 | 15:00 | 27.6°C | 30.1°C | 0.01 | 1.8 | ESE | 63 | 1018 |
| 12:00 | 16:00 | 28.7°C | 31.5°C | 0.06 | 1.6 | SE | 61 | 1018 |
| 13:00 | 17:00 | 30°C | 32.5°C | 0.05 | 2.1 | SE | 58 | 1018 |
| 14:00 | 18:00 | 30.8°C | 33.1°C | 0.09 | 2.4 | SE | 55 | 1018 |
| 15:00 | 19:00 | 31.1°C | 33.4°C | 0.02 | 2.5 | SE | 54 | 1017 |
| 16:00 | 20:00 | 30.6°C | 32.4°C | 0.03 | 2.7 | SE | 54 | 1016 |
| 17:00 | 21:00 | 29.2°C | 32.3°C | 0.02 | 3.1 | SE | 69 | 1016 |
| 18:00 | 22:00 | 28.6°C | 31.9°C | 0.39 | 2.1 | SE | 68 | 1015 |
| 19:00 | 23:00 | 28.7°C | 31.8°C | 0.04 | 2.4 | SE | 68 | 1016 |
| 20:00 | 00:00 | 28.2°C | 31.9°C | 0 | 1.4 | ESE | 68 | 1016 |
| 21:00 | 01:00 | 27.2°C | 30.1°C | 0.05 | 1.9 | E | 70 | 1016 |
| 22:00 | 02:00 | 26.7°C | 29.1°C | 0 | 2.5 | ESE | 71 | 1017 |
| 23:00 | 03:00 | 25.9°C | 29.2°C | 0 | 2.3 | SE | 80 | 1016 |
Nearby cities
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Data 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
- Potomac — 39.000°, -77.250°, ERA5 grid cell center, 4.1 km from requested point
- Time zone
- America/New_York
- What's shown here
- The hourly and daily record for 7 July 2020 specifically — not a monthly average. See the Potomac climate overview for typical conditions.
- 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 (2026-07-21). Historical climate data for Potomac, United States (39.00°N, 77.25°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Potomac, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 21, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Potomac, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 21, 2026, www.pastclimate.com.
@misc{pastclimate,
author = {PastClimate},
title = {Historical climate data for Potomac, United States},
year = {2026},
note = {Derived from ERA5 (Hersbach et al., 2023), Copernicus Climate Change Service. Accessed 2026-07-21},
url = {https://www.pastclimate.com/}
}Notice something wrong with this data? Report a data issue.