Home / Copperopolis / 31 December 2017
Copperopolis
United States · 31 December 2017
← 30 December 20171 January 2018 →
Average
8.6°C
low 2.8° · high 16°
Rainfall
0mm
dry day
Wind
1.2m/s
daily average
Humidity
74.3%
daily average
Cloud
73%
cover
Pressure
1018hPa
daily average
The temperature ranged from 2.8°C around 06:00 to 16°C around 14:00. No measurable rain was recorded during the day.
How unusual was this day?
Compared against the same 135 calendar days (±7 days) across the other 9 years on file.
High temperature
90th percentile
Low temperature
25th percentile
Rainfall
50th percentile
Wind
9th 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 8.8°C, versus 8.6°C on this specific day.
Sun & daylight
Sunrise
07:18
Sunset
16:53
Day length
9h 35m
Hour by hour
Temperature (line) and hourly rainfall (bars), local time — America/Los_Angeles.
Cumulative rainfall through the day.
| Local time | UTC | Temp °C | Feels °C | Rain mm | Wind m/s | Dir | Humidity % | Pressure hPa |
|---|---|---|---|---|---|---|---|---|
| 00:00 | 08:00 | 5.9 | 4 | 0 | 0.7 | ENE | 84 | 1017 |
| 01:00 | 09:00 | 5.1 | 3.1 | 0 | 0.8 | ENE | 88 | 1017 |
| 02:00 | 10:00 | 4.3 | 1.7 | 0 | 1.6 | ENE | 90 | 1017 |
| 03:00 | 11:00 | 4.4 | 1.8 | 0 | 1.5 | ENE | 91 | 1017 |
| 04:00 | 12:00 | 3.6 | 0.9 | 0 | 1.5 | ENE | 92 | 1017 |
| 05:00 | 13:00 | 3.2 | 0.4 | 0 | 1.6 | ENE | 92 | 1017 |
| 06:00 | 14:00 | 2.8 | 0.1 | 0 | 1.4 | ENE | 93 | 1017 |
| 07:00 | 15:00 | 3.4 | 0.9 | 0 | 0.9 | ENE | 83 | 1018 |
| 08:00 | 16:00 | 4.3 | 2 | 0 | 0.7 | ENE | 80 | 1018 |
| 09:00 | 17:00 | 7.1 | 5.2 | 0 | 0.8 | ENE | 80 | 1018 |
| 10:00 | 18:00 | 10.8 | 9.8 | 0 | 0.1 | NE | 73 | 1019 |
| 11:00 | 19:00 | 12.2 | 10.7 | 0 | 0.4 | WNW | 59 | 1019 |
| 12:00 | 20:00 | 14 | 12.7 | 0 | 0.4 | NNW | 56 | 1018 |
| 13:00 | 21:00 | 15.8 | 13.9 | 0 | 0.6 | WNW | 43 | 1018 |
| 14:00 | 22:00 | 16 | 13.8 | 0 | 1.2 | NW | 45 | 1017 |
| 15:00 | 23:00 | 16 | 13.1 | 0 | 2.3 | WNW | 45 | 1017 |
| 16:00 | 00:00 | 15.1 | 13.2 | 0 | 1.7 | NW | 59 | 1018 |
| 17:00 | 01:00 | 13.3 | 11 | 0 | 1.9 | N | 59 | 1018 |
| 18:00 | 02:00 | 12 | 9.9 | 0 | 1.5 | NNE | 63 | 1018 |
| 19:00 | 03:00 | 8.8 | 7 | 0 | 1 | NNW | 80 | 1019 |
| 20:00 | 04:00 | 7.4 | 5.3 | 0 | 1.3 | NNW | 83 | 1019 |
| 21:00 | 05:00 | 6.8 | 4.4 | 0 | 1.5 | NNE | 84 | 1020 |
| 22:00 | 06:00 | 7.1 | 4.8 | 0 | 1.4 | NE | 81 | 1021 |
| 23:00 | 07:00 | 7.4 | 5.4 | 0 | 1 | NE | 79 | 1021 |
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
- Copperopolis — 38.000°, -120.750°, ERA5 grid cell center, 9.7 km from requested point
- Time zone
- America/Los_Angeles
- What's shown here
- The hourly and daily record for 31 December 2017 specifically — not a monthly average. See the Copperopolis 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 (2026-07-17). Historical climate data for Copperopolis, United States (38.00°N, 120.75°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Copperopolis, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 17, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Copperopolis, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 17, 2026, www.pastclimate.com.
@misc{pastclimate,
author = {PastClimate},
title = {Historical climate data for Copperopolis, United States},
year = {2026},
note = {Derived from ERA5 (Hersbach et al., 2023), Copernicus Climate Change Service. Accessed 2026-07-17},
url = {https://www.pastclimate.com/}
}Notice something wrong with this data? Report a data issue.