Home / Blackhawk / 31 December 2019
Blackhawk
United States · 31 December 2019
← 30 December 20191 January 2020 →
Average
9.9°C
low 3.8° · high 16.2°
Rainfall
0mm
dry day
Wind
1.2m/s
daily average
Humidity
66.4%
daily average
Cloud
43%
cover
Pressure
1021hPa
daily average
The temperature ranged from 3.8°C around 04:00 to 16.2°C around 17:00. 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
91th percentile
Low temperature
24th percentile
Rainfall
45th percentile
Wind
12th 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 9.5°C, versus 9.9°C on this specific day.
Sun & daylight
Sunrise
07:23
Sunset
16:58
Day length
9h 36m
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 | 9.4 | 7.7 | 0 | 0.9 | W | 74 | 1020 |
| 01:00 | 09:00 | 7.2 | 4.9 | 0 | 1.3 | ENE | 78 | 1020 |
| 02:00 | 10:00 | 8.3 | 6.1 | 0 | 1.3 | ESE | 76 | 1020 |
| 03:00 | 11:00 | 7.8 | 5.3 | 0 | 1.6 | ESE | 76 | 1021 |
| 04:00 | 12:00 | 3.8 | 0.8 | 0 | 1.6 | SE | 83 | 1020 |
| 05:00 | 13:00 | 5.2 | 2.7 | 0 | 1.1 | SSE | 77 | 1020 |
| 06:00 | 14:00 | 5.4 | 3 | 0 | 0.9 | SSE | 77 | 1021 |
| 07:00 | 15:00 | 4.5 | 1.7 | 0 | 1.5 | SE | 81 | 1021 |
| 08:00 | 16:00 | 5.8 | 3.3 | 0 | 1.4 | SE | 81 | 1021 |
| 09:00 | 17:00 | 8.8 | 6.7 | 0 | 1.2 | ESE | 74 | 1021 |
| 10:00 | 18:00 | 10.8 | 9.2 | 0 | 0.5 | E | 63 | 1022 |
| 11:00 | 19:00 | 12.1 | 9.9 | 0 | 1.1 | N | 55 | 1022 |
| 12:00 | 20:00 | 13.1 | 10.9 | 0 | 1.3 | NNE | 54 | 1021 |
| 13:00 | 21:00 | 14.5 | 11.8 | 0 | 1.4 | N | 43 | 1021 |
| 14:00 | 22:00 | 15.7 | 14.2 | 0 | 0.4 | NNW | 46 | 1020 |
| 15:00 | 23:00 | 15.9 | 14.5 | 0 | 0.2 | SW | 46 | 1020 |
| 16:00 | 00:00 | 15.6 | 13.9 | 0 | 1 | SSE | 52 | 1020 |
| 17:00 | 01:00 | 16.2 | 14.2 | 0 | 0.7 | S | 40 | 1020 |
| 18:00 | 02:00 | 12.3 | 10 | 0 | 1.1 | SSE | 54 | 1020 |
| 19:00 | 03:00 | 9.5 | 7.4 | 0 | 1.2 | SSW | 70 | 1020 |
| 20:00 | 04:00 | 9.3 | 6.9 | 0 | 1.5 | S | 71 | 1021 |
| 21:00 | 05:00 | 10 | 7.4 | 0 | 1.9 | S | 69 | 1020 |
| 22:00 | 06:00 | 8.4 | 6.2 | 0 | 1.2 | S | 73 | 1021 |
| 23:00 | 07:00 | 7.1 | 4.8 | 0 | 1.4 | SSE | 78 | 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
- Blackhawk — 37.750°, -122.000°, ERA5 grid cell center, 11.3 km from requested point
- Time zone
- America/Los_Angeles
- What's shown here
- The hourly and daily record for 31 December 2019 specifically — not a monthly average. See the Blackhawk 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 Blackhawk, United States (37.75°N, 122.00°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Blackhawk, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 17, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Blackhawk, 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 Blackhawk, 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.