Home / Arnold / 21 October 2017
Arnold
United States · 21 October 2017
← 20 October 201722 October 2017 →
Average
8°C
low 0.8°C · high 17°C
Rainfall
0mm
dry day
Wind
2.2m/s
daily average
Humidity
57.9%
daily average
Cloud
6%
cover
Pressure
1021hPa
daily average
The temperature ranged from 0.8°C around 05:00 to 17°C around 15:00. 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
32th percentile
Low temperature
7th percentile
Rainfall
76th percentile
Wind
48th 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 11.8°C, versus 8°C on this specific day.
Sun & daylight
Sunrise
07:16
Sunset
18:14
Day length
10h 58m
Hour by hour
Temperature (line) and hourly rainfall (bars), local time — America/Los_Angeles.
Cumulative rainfall through the day.
| Local time | UTC | Temp | Feels | Rain mm | Wind m/s | Dir | Humidity % | Pressure hPa |
|---|---|---|---|---|---|---|---|---|
| 00:00 | 07:00 | 2.7°C | -0.8°C | 0 | 1.9 | NE | 78 | 1020 |
| 01:00 | 08:00 | 2.7°C | -1°C | 0 | 2.2 | NE | 75 | 1020 |
| 02:00 | 09:00 | 2.5°C | -1.5°C | 0 | 2.4 | NE | 70 | 1020 |
| 03:00 | 10:00 | 1.4°C | -2.9°C | 0 | 2.8 | ENE | 75 | 1020 |
| 04:00 | 11:00 | 1.1°C | -3.2°C | 0 | 2.7 | NE | 70 | 1019 |
| 05:00 | 12:00 | 0.8°C | -3.5°C | 0 | 2.6 | NE | 68 | 1020 |
| 06:00 | 13:00 | 1.1°C | -3.5°C | 0 | 2.8 | ENE | 64 | 1020 |
| 07:00 | 14:00 | 1.4°C | -2.8°C | 0 | 2.2 | NE | 60 | 1020 |
| 08:00 | 15:00 | 2.8°C | -1.5°C | 0 | 2.1 | NE | 50 | 1021 |
| 09:00 | 16:00 | 7.1°C | 3.7°C | 0 | 1.3 | NE | 46 | 1022 |
| 10:00 | 17:00 | 10.4°C | 6.9°C | 0 | 1.2 | NW | 30 | 1022 |
| 11:00 | 18:00 | 12.8°C | 9.1°C | 0 | 2.1 | WNW | 36 | 1021 |
| 12:00 | 19:00 | 13.9°C | 10°C | 0 | 3 | WNW | 40 | 1021 |
| 13:00 | 20:00 | 14.6°C | 10.7°C | 0 | 3.2 | WNW | 42 | 1021 |
| 14:00 | 21:00 | 16.4°C | 12.3°C | 0 | 3 | WNW | 32 | 1021 |
| 15:00 | 22:00 | 17°C | 13.4°C | 0 | 2.8 | WNW | 38 | 1021 |
| 16:00 | 23:00 | 16.2°C | 12.6°C | 0 | 2.9 | WNW | 40 | 1021 |
| 17:00 | 00:00 | 14.8°C | 11.3°C | 0 | 2.7 | WNW | 44 | 1022 |
| 18:00 | 01:00 | 13.3°C | 10.7°C | 0 | 1.7 | WNW | 52 | 1023 |
| 19:00 | 02:00 | 12.2°C | 10°C | 0 | 1.1 | NNE | 54 | 1023 |
| 20:00 | 03:00 | 8°C | 5.7°C | 0 | 1.6 | NE | 78 | 1024 |
| 21:00 | 04:00 | 6.8°C | 4.2°C | 0 | 1.8 | NE | 81 | 1024 |
| 22:00 | 05:00 | 6.4°C | 3.9°C | 0 | 1.6 | ENE | 81 | 1024 |
| 23:00 | 06:00 | 6°C | 3.6°C | 0 | 1.3 | ENE | 84 | 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
- Arnold — 38.250°, -120.250°, ERA5 grid cell center, 8.8 km from requested point
- Time zone
- America/Los_Angeles
- What's shown here
- The hourly and daily record for 21 October 2017 specifically — not a monthly average. See the Arnold 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 (2026-07-20). Historical climate data for Arnold, United States (38.25°N, 120.25°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Arnold, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 20, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Arnold, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 20, 2026, www.pastclimate.com.
@misc{pastclimate,
author = {PastClimate},
title = {Historical climate data for Arnold, United States},
year = {2026},
note = {Derived from ERA5 (Hersbach et al., 2023), Copernicus Climate Change Service. Accessed 2026-07-20},
url = {https://www.pastclimate.com/}
}Notice something wrong with this data? Report a data issue.