Simi Valley weather in April

In April, Simi Valley sees average daytime highs of 70°F and overnight lows near 50°F, with 0.9 in of rain across 2.9 wet days and about 12.8 hours of daylight. It is the 7th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 67°F in the first days to 72°F by the end. The sky is clear or mostly clear about 60% of the time in April, and the air most often feels dry.

Daylight stretches from about 12 h 18 min at the start of April to 13 h 18 min by month's end. Set against the rest of the year, April is Simi Valley's 8th-clearest and 4th-windiest month. For the whole year in context, see Simi Valley's year-round climate.

Daytime high
70°
7th warmest
Overnight low
50°
6th coldest
Rainfall
0.9 in
2.9 wet days
Daylight
12 h 54 min
5:30 AM – 6:21 PM
Cloud cover
35%
8th clearest
Wind
4 mph
4th windiest
Solar energy
6.88 kWh/m²
Travel score
8.0
out of 10

Simi Valley is city in Ventura County, California, United States.

Density
1,159/km²
people per km²
Founded
1969

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in April

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 67°F in the first days to 72°F by the end.

A typical April day in Simi Valley reaches about 70°F in the afternoon and slips back to 50°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 60°F and 81°F. Set against its neighbours, April runs about 4°F warmer than March and about 3°F cooler than May.

40°50°60°70°80°151015202530
Avg high (°F)Avg low (°F)
16748
26748
36748
46748
56849
66849
76849
86849
96849
106849
116949
126949
136949
146949
156950
167050
177050
187050
197150
207151
217151
227151
237151
247251
257252
267252
277252
287252
297352
307353

Simi Valley weather by month

How April compares with the rest of the year at a glance. April is the 7th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan63° / 45°3.65.6106.4
Feb64° / 45°3.86.410.76.4
Mar66° / 47°2.65.611.77.0
Apr70° / 50°0.92.912.88.0
May73° / 55°0.51.813.88.7
Jun78° / 59°0.10.514.29.1
Jul83° / 64°0.10.514.18.1
Aug85° / 65°0.00.113.37.4
Sep83° / 62°0.20.612.28.2
Oct77° / 56°0.82.111.18.8
Nov70° / 49°0.82.610.28.1
Dec63° / 44°2.34.89.86.6

Cloud cover in April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 60% of the time in April.

Beyond those clear spells, partly cloudy skies cover about 14% of April, with mostly cloudy or overcast conditions the remaining 26%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17030
27129
37129
47129
57228
67228
77327
87327
97327
107426
117426
127327
137426
147426
157525
167525
177525
187525
197525
207525
217525
227624
237624
247624
257624
267723
277723
287723
297624
307624

Chance of precipitation in April

Any precipitation

Simi Valley gets around 0.9 in of rain over 2.9 wet days in April. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 10% and peaks near 14% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
114
214
314
413
513
613
713
813
912
1012
1112
1212
1311
1411
1510
1610
179
189
198
208
218
227
237
247
257
267
277
287
297
307

Humidity in April

DryComfortableHumidMuggyOppressiveMiserable

Most of April feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, April lands in the dry band about 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22982
23982
24982
25973
26973
27973
28964
29964
30955

Wind in April

Winds average 4 mph in April.

Across April, daily wind ranges from about 4 mph on the calmest days to 4 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm

Sunrise & sunset in April

DaylightNight

Daylight runs from about 12 h 18 min at the start of April to 13 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over April. Sunrise moves from 5:50 AM to 5:13 AM, and sunset from 6:09 PM to 6:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:506:09
212.45:496:10
312.45:476:11
412.45:466:12
512.55:456:12
612.55:436:13
712.55:426:14
812.65:406:15
912.65:396:16
1012.65:386:16
1112.75:366:17
1212.75:356:18
1312.85:346:19
1412.85:326:19
1512.85:316:20
1612.95:306:21
1712.95:286:22
1812.95:276:23
1913.05:266:23
2013.05:256:24
2113.05:236:25
2213.15:226:26
2313.15:216:27
2413.15:206:27
2513.25:186:28
2613.25:176:29
2713.25:166:30
2813.35:156:31
2913.35:146:31
3013.35:136:32

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 6.88 kWh/m².

For context, solar energy here swings from a low near 2.96 kWh/m² to a high of 8.09 kWh/m² in June across the year — April's 6.88 kWh/m² falls in the middle.

02468151015202530
Solar energy (kWh/m²)Level
16.2Intense
26.3Intense
36.3Intense
46.4Intense
56.4Intense
66.5Intense
76.5Intense
86.6Intense
96.6Intense
106.7Intense
116.7Intense
126.7Intense
136.8Intense
146.8Intense
156.9Intense
166.9Intense
177.0Intense
187.0Intense
197.0Intense
207.1Intense
217.1Intense
227.1Intense
237.2Intense
247.2Intense
257.2Intense
267.3Intense
277.3Intense
287.3Intense
297.3Intense
307.3Intense
Planning a trip in April

Is April a good time to visit Simi Valley?

Our two travel scores rate April for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

8.0
Sightseeing
7th-best month of the year
4.8
Beach & pool
7th-best month of the year

April is one of the better times to visit Simi Valley for general sightseeing.

What to pack for Simi Valley in April

From April's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In April, Simi Valley sees daytime highs around 70°F and nights near 50°F. Pack sun protection.

sun protection

Sea temperature near Simi Valley in April

The nearest coast averages about 58°F in April — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 22 mi away) is warmest in August at about 67°F and coldest in March near 58°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

55°60°65°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°F)Comfort
Jan58Bracing
Feb58Bracing
Mar58Bracing
Apr58Bracing
May60Cool
Jun63Cool
Jul66Cool
Aug67Cool
Sep67Cool
Oct65Cool
Nov62Cool
Dec60Cool

UV index in Simi Valley in April

LowModerateHighVery highExtreme

Clear-sky midday UV in April peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Simi Valley peaks around June 23 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 11Dec 15UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar5Moderate
Apr8Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Simi Valley in April

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where April falls, not just the annual average.

Air quality in Simi Valley is worst in December — around 29 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (May, 12 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateDec 1428 µg/m³May 1812 µg/m³
PM2.5 (µg/m³)Level
Jan18Moderate
Feb17Moderate
Mar17Moderate
Apr15Moderate
May12Good
Jun14Moderate
Jul25Moderate
Aug26Moderate
Sep24Moderate
Oct18Moderate
Nov23Moderate
Dec29Moderate
Location & terrain

Where is Simi Valley?

Simi Valley sits at 34.3°N, 118.8°W, 768 ft above sea level, in United States. The nearest listed city is Moorpark, 5.6 mi away.

Topography around Simi Valley

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Simi Valley.

Within 2 miles, the terrain around Simi Valley has only modest variations in elevation — a maximum elevation change of 656 ft around an average of 886 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,028 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 8,816 ft.

The land around Simi Valley is covered by artificial surfaces (56%) within 2 miles, grassland (39%) and shrubs (21%) within 10 miles, and water (30%) and grassland (23%) within 50 miles.

2 miles
656 ft
10 miles
3,028 ft
50 miles
8,816 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
April weather nearby: Moorpark 5.6 mi · Thousand Oaks 7.5 mi · Agoura 9.3 mi · Agoura Hills 9.3 mi · West Hills 9.3 mi · Chatsworth 11 mi · Calabasas 11 mi · Canoga Park 11 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Simi Valley (34.2694°, -118.7815°, elevation 768 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).