Home / Cornwall / 4 September 2018
Cornwall
United States · 4 September 2018
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Average
27.5°C
low 22.4°C · high 33.4°C
Rainfall
3.1mm
rain recorded
Wind
1.4m/s
daily average
Humidity
77.9%
daily average
Cloud
31%
cover
Pressure
1024hPa
daily average
The temperature ranged from 22.4°C around 05:00 to 33.4°C around 15:00. Rain was recorded across 2 hours, from around 17:00 to 18:00 (3.1mm total).
How unusual was this day?
Compared against the same 135 calendar days (±7 days) across the other 9 years on file.
High temperature
96th percentile
Low temperature
93th percentile
Rainfall
77th percentile
Wind
6th 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 21.7°C, versus 27.5°C on this specific day.
Sun & daylight
Sunrise
06:36
Sunset
19:32
Day length
12h 57m
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 | 25.3°C | 30°C | 0 | 1.4 | W | 91 | 1024 |
| 01:00 | 05:00 | 24.8°C | 29.2°C | 0 | 1.5 | WNW | 91 | 1024 |
| 02:00 | 06:00 | 24.2°C | 28.3°C | 0 | 1.5 | NW | 92 | 1024 |
| 03:00 | 07:00 | 24°C | 28°C | 0 | 1.3 | NNW | 92 | 1024 |
| 04:00 | 08:00 | 22.9°C | 26.6°C | 0 | 1.1 | NNW | 92 | 1024 |
| 05:00 | 09:00 | 22.4°C | 25.9°C | 0 | 1.2 | NW | 94 | 1024 |
| 06:00 | 10:00 | 22.5°C | 24.3°C | 0 | 2.9 | NNE | 87 | 1023 |
| 07:00 | 11:00 | 22.9°C | 25.3°C | 0 | 2.2 | NNE | 87 | 1024 |
| 08:00 | 12:00 | 24.2°C | 27.7°C | 0 | 1.9 | NE | 89 | 1025 |
| 09:00 | 13:00 | 26.1°C | 30.8°C | 0 | 1.3 | NE | 87 | 1025 |
| 10:00 | 14:00 | 27.6°C | 32.6°C | 0 | 1.1 | NE | 80 | 1025 |
| 11:00 | 15:00 | 30.3°C | 34°C | 0 | 0.9 | NE | 59 | 1025 |
| 12:00 | 16:00 | 31.6°C | 35.5°C | 0 | 1 | N | 56 | 1025 |
| 13:00 | 17:00 | 32.4°C | 35.7°C | 0.02 | 1.3 | NNW | 52 | 1024 |
| 14:00 | 18:00 | 32.7°C | 36°C | 0 | 1.6 | NNW | 52 | 1024 |
| 15:00 | 19:00 | 33.4°C | 36.7°C | 0.03 | 1.9 | NNW | 51 | 1023 |
| 16:00 | 20:00 | 33.3°C | 36.4°C | 0.01 | 1.9 | NNW | 50 | 1023 |
| 17:00 | 21:00 | 33.3°C | 37.1°C | 1.08 | 1.9 | N | 55 | 1023 |
| 18:00 | 22:00 | 30.7°C | 37.9°C | 1.94 | 1.3 | NNE | 84 | 1022 |
| 19:00 | 23:00 | 29.6°C | 36.4°C | 0.02 | 0.7 | NNW | 83 | 1023 |
| 20:00 | 00:00 | 27.4°C | 32.8°C | 0 | 1 | NW | 84 | 1022 |
| 21:00 | 01:00 | 26.5°C | 31.6°C | 0 | 0.7 | WNW | 84 | 1023 |
| 22:00 | 02:00 | 26.3°C | 31.2°C | 0 | 1 | N | 85 | 1023 |
| 23:00 | 03:00 | 25°C | 29.9°C | 0 | 1.3 | N | 95 | 1024 |
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
- Cornwall — 40.250°, -76.500°, ERA5 grid cell center, 8.4 km from requested point
- Time zone
- America/New_York
- What's shown here
- The hourly and daily record for 4 September 2018 specifically — not a monthly average. See the Cornwall 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 (2026-07-19). Historical climate data for Cornwall, United States (40.25°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 Cornwall, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 19, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Cornwall, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 19, 2026, www.pastclimate.com.
@misc{pastclimate,
author = {PastClimate},
title = {Historical climate data for Cornwall, United States},
year = {2026},
note = {Derived from ERA5 (Hersbach et al., 2023), Copernicus Climate Change Service. Accessed 2026-07-19},
url = {https://www.pastclimate.com/}
}Notice something wrong with this data? Report a data issue.