Home / Simi Valley / 26 December 2017

Simi Valley

United States · 26 December 2017

← 25 December 201727 December 2017 →

Average

12.5°C

low 5.8° · high 20.7°

Rainfall

0mm

dry day

Wind

1.3m/s

daily average

Humidity

50.8%

daily average

Cloud

44%

cover

Pressure

1019hPa

daily average

The temperature ranged from 5.8°C around 04:00 to 20.7°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

86th percentile

Low temperature

22th percentile

Rainfall

61th percentile

Wind

18th 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 12.5°C on this specific day.

Sun & daylight

Sunrise

06:59

Sunset

16:52

Day length

9h 53m

Hour by hour

Temperature (line) and hourly rainfall (bars), local time — America/Los_Angeles.

↓ Download CSV
00:0006:0012:0018:0023:00

Cumulative rainfall through the day.

00:0006:0012:0018:0023:00
Local timeUTCTemp °CFeels °CRain mmWind m/sDirHumidity %Pressure hPa
00:0008:009.36.601.5N611019
01:0009:007.85.101.3N631018
02:0010:006.43.501.9N761019
03:0011:006.23.501.5NNE771019
04:0012:005.82.901.5NNE701019
05:0013:006.33.301.6NNE661019
06:0014:006.83.801.6NNE671019
07:0015:007.34.301.6NNE641019
08:0016:008.75.601.8NNE571020
09:0017:0011.78.401.4NNE371020
10:0018:001512.200.5N281021
11:0019:0017.114.700.1ENE261020
12:0020:0018.315.600.5SW241019
13:0021:0020.117.100.9SW201018
14:0022:0020.718.200.9S281018
15:0023:0020.518.201.1SSE301018
16:0000:0019.817.301.1S311018
17:0001:0018.215.601.5SW361019
18:0002:0015.713.501.4WSW471019
19:0003:0013.811.801.4NNW571019
20:0004:0013.311.201.5N571020
21:0005:0010.98.601.5N641020
22:0006:0010.17.801.4N661020
23:0007:009.87.501.5N681020

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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
Simi Valley — 34.250°, -118.750°, ERA5 grid cell center, 3.6 km from requested point
Time zone
America/Los_Angeles
What's shown here
The hourly and daily record for 26 December 2017 specifically — not a monthly average. See the Simi Valley 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

Plain text
PastClimate (2026-07-17). Historical climate data for Simi Valley, United States (34.25°N, 118.75°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
APA
PastClimate. (2026). Historical climate data for Simi Valley, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 17, 2026, from https://www.pastclimate.com/
MLA
"Historical Climate Data for Simi Valley, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 17, 2026, www.pastclimate.com.
BibTeX
@misc{pastclimate,
  author = {PastClimate},
  title = {Historical climate data for Simi Valley, 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/}
}

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