Simi Valley weather in May
In May, Simi Valley sees average daytime highs of 73°F and overnight lows near 55°F, with 0.5 in of rain across 1.8 wet days and about 13.8 hours of daylight. It is the 6th-warmest and 8th-wettest month of the year here.
Day-to-day highs hold fairly steady near 73°F through the month. The sky is clear or mostly clear about 65% of the time in May, and the air most often feels dry.
Daylight stretches from about 13 h 24 min at the start of May to 14 h 06 min by month's end. Set against the rest of the year, May is Simi Valley's 6th-clearest and 7th-windiest month. For the whole year in context, see Simi Valley's year-round climate.
- Daytime high
- 73°
- 6th warmest
- Overnight low
- 55°
- 7th coldest
- Rainfall
- 0.5 in
- 1.8 wet days
- Daylight
- 13 h 48 min
- 4:58 AM – 6:45 PM
- Cloud cover
- 31%
- 6th clearest
- Wind
- 4 mph
- 7th windiest
- Solar energy
- 7.6 kWh/m²
- Travel score
- 8.7
- 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 May
Day-to-day highs hold fairly steady near 73°F through the month.
A typical May day in Simi Valley reaches about 73°F in the afternoon and slips back to 55°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 64°F and 83°F. Set against its neighbours, May runs about 3°F warmer than April and about 5°F cooler than June.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 74 | 74 | 74 | 74 | 74 | 74 |
| Avg low (°F) | 53 | 53 | 53 | 53 | 53 | 53 | 54 | 54 | 54 | 54 | 54 | 54 | 54 | 54 | 54 | 54 | 55 | 55 | 55 | 55 | 55 | 55 | 55 | 55 | 55 | 55 | 56 | 56 | 56 | 56 | 56 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 73 | 53 |
| 2 | 73 | 53 |
| 3 | 73 | 53 |
| 4 | 73 | 53 |
| 5 | 73 | 53 |
| 6 | 73 | 53 |
| 7 | 73 | 54 |
| 8 | 73 | 54 |
| 9 | 73 | 54 |
| 10 | 73 | 54 |
| 11 | 73 | 54 |
| 12 | 73 | 54 |
| 13 | 73 | 54 |
| 14 | 73 | 54 |
| 15 | 73 | 54 |
| 16 | 73 | 54 |
| 17 | 73 | 55 |
| 18 | 73 | 55 |
| 19 | 73 | 55 |
| 20 | 73 | 55 |
| 21 | 73 | 55 |
| 22 | 73 | 55 |
| 23 | 73 | 55 |
| 24 | 73 | 55 |
| 25 | 73 | 55 |
| 26 | 74 | 55 |
| 27 | 74 | 56 |
| 28 | 74 | 56 |
| 29 | 74 | 56 |
| 30 | 74 | 56 |
| 31 | 74 | 56 |
Simi Valley weather by month
How May compares with the rest of the year at a glance. May is the 6th-warmest and 8th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 63° / 45° | 3.6 | 5.6 | 10 | 6.4 |
| Feb | 64° / 45° | 3.8 | 6.4 | 10.7 | 6.4 |
| Mar | 66° / 47° | 2.6 | 5.6 | 11.7 | 7.0 |
| Apr | 70° / 50° | 0.9 | 2.9 | 12.8 | 8.0 |
| May | 73° / 55° | 0.5 | 1.8 | 13.8 | 8.7 |
| Jun | 78° / 59° | 0.1 | 0.5 | 14.2 | 9.1 |
| Jul | 83° / 64° | 0.1 | 0.5 | 14.1 | 8.1 |
| Aug | 85° / 65° | 0.0 | 0.1 | 13.3 | 7.4 |
| Sep | 83° / 62° | 0.2 | 0.6 | 12.2 | 8.2 |
| Oct | 77° / 56° | 0.8 | 2.1 | 11.1 | 8.8 |
| Nov | 70° / 49° | 0.8 | 2.6 | 10.2 | 8.1 |
| Dec | 63° / 44° | 2.3 | 4.8 | 9.8 | 6.6 |
Cloud cover in May
The sky is clear or mostly clear about 65% of the time in May.
Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 22%. Skies tend to open up as the month goes on.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 75 | 75 | 76 | 76 | 76 | 76 | 77 | 76 | 76 | 76 | 77 | 77 | 78 | 78 | 78 | 78 | 79 | 79 | 79 | 79 | 79 | 79 | 79 | 81 | 81 | 81 | 82 | 82 | 82 | 82 | 83 |
| Cloudier (%) | 25 | 25 | 24 | 24 | 24 | 24 | 23 | 24 | 24 | 24 | 23 | 23 | 22 | 22 | 22 | 22 | 21 | 21 | 21 | 21 | 21 | 21 | 21 | 19 | 19 | 19 | 18 | 18 | 18 | 18 | 17 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 75 | 25 |
| 2 | 75 | 25 |
| 3 | 76 | 24 |
| 4 | 76 | 24 |
| 5 | 76 | 24 |
| 6 | 76 | 24 |
| 7 | 77 | 23 |
| 8 | 76 | 24 |
| 9 | 76 | 24 |
| 10 | 76 | 24 |
| 11 | 77 | 23 |
| 12 | 77 | 23 |
| 13 | 78 | 22 |
| 14 | 78 | 22 |
| 15 | 78 | 22 |
| 16 | 78 | 22 |
| 17 | 79 | 21 |
| 18 | 79 | 21 |
| 19 | 79 | 21 |
| 20 | 79 | 21 |
| 21 | 79 | 21 |
| 22 | 79 | 21 |
| 23 | 79 | 21 |
| 24 | 81 | 19 |
| 25 | 81 | 19 |
| 26 | 81 | 19 |
| 27 | 82 | 18 |
| 28 | 82 | 18 |
| 29 | 82 | 18 |
| 30 | 82 | 18 |
| 31 | 83 | 17 |
Chance of precipitation in May
Simi Valley gets around 0.5 in of rain over 1.8 wet days in May. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 6% and peaks near 7% on the wettest days.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 5 | 5 | 5 | 4 | 4 | 4 | 3 | 3 | 3 |
| Rain chance (%) | |
|---|---|
| 1 | 7 |
| 2 | 7 |
| 3 | 7 |
| 4 | 7 |
| 5 | 7 |
| 6 | 7 |
| 7 | 7 |
| 8 | 7 |
| 9 | 7 |
| 10 | 7 |
| 11 | 7 |
| 12 | 7 |
| 13 | 7 |
| 14 | 7 |
| 15 | 7 |
| 16 | 6 |
| 17 | 6 |
| 18 | 6 |
| 19 | 6 |
| 20 | 6 |
| 21 | 6 |
| 22 | 6 |
| 23 | 5 |
| 24 | 5 |
| 25 | 5 |
| 26 | 4 |
| 27 | 4 |
| 28 | 4 |
| 29 | 3 |
| 30 | 3 |
| 31 | 3 |
Humidity in May
Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, May lands in the dry band about 82% of days. It rarely turns muggy — the humid and sticky bands barely register.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 95 | 94 | 93 | 93 | 92 | 91 | 90 | 89 | 89 | 88 | 87 | 86 | 85 | 84 | 83 | 83 | 82 | 81 | 80 | 78 | 77 | 77 | 76 | 75 | 74 | 73 | 71 | 70 | 69 | 68 | 67 |
| Comfortable (%) | 5 | 6 | 7 | 7 | 8 | 9 | 10 | 11 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 17 | 18 | 19 | 20 | 21 | 22 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 |
| Humid (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 2 |
| Dry (%) | Comfortable (%) | Humid (%) | |
|---|---|---|---|
| 1 | 95 | 5 | 0 |
| 2 | 94 | 6 | 0 |
| 3 | 93 | 7 | 0 |
| 4 | 93 | 7 | 0 |
| 5 | 92 | 8 | 0 |
| 6 | 91 | 9 | 0 |
| 7 | 90 | 10 | 0 |
| 8 | 89 | 11 | 0 |
| 9 | 89 | 11 | 0 |
| 10 | 88 | 12 | 0 |
| 11 | 87 | 13 | 0 |
| 12 | 86 | 14 | 0 |
| 13 | 85 | 15 | 0 |
| 14 | 84 | 16 | 0 |
| 15 | 83 | 17 | 0 |
| 16 | 83 | 17 | 0 |
| 17 | 82 | 18 | 0 |
| 18 | 81 | 19 | 0 |
| 19 | 80 | 20 | 0 |
| 20 | 78 | 21 | 1 |
| 21 | 77 | 22 | 1 |
| 22 | 77 | 22 | 1 |
| 23 | 76 | 23 | 1 |
| 24 | 75 | 24 | 1 |
| 25 | 74 | 25 | 1 |
| 26 | 73 | 26 | 1 |
| 27 | 71 | 27 | 2 |
| 28 | 70 | 28 | 2 |
| 29 | 69 | 29 | 2 |
| 30 | 68 | 30 | 2 |
| 31 | 67 | 31 | 2 |
Wind in May
Winds average 4 mph in May.
Across May, 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.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 4 | calm |
| 2 | 4 | calm |
| 3 | 4 | calm |
| 4 | 4 | calm |
| 5 | 4 | calm |
| 6 | 4 | calm |
| 7 | 4 | calm |
| 8 | 4 | calm |
| 9 | 4 | calm |
| 10 | 4 | calm |
| 11 | 4 | calm |
| 12 | 4 | calm |
| 13 | 4 | calm |
| 14 | 4 | calm |
| 15 | 4 | calm |
| 16 | 4 | calm |
| 17 | 4 | calm |
| 18 | 4 | calm |
| 19 | 4 | calm |
| 20 | 4 | calm |
| 21 | 4 | calm |
| 22 | 4 | calm |
| 23 | 4 | calm |
| 24 | 4 | calm |
| 25 | 4 | calm |
| 26 | 4 | calm |
| 27 | 4 | calm |
| 28 | 4 | calm |
| 29 | 4 | calm |
| 30 | 4 | calm |
| 31 | 4 | calm |
Sunrise & sunset in May
Daylight runs from about 13 h 24 min at the start of May to 14 h 06 min by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 42 minutes over May. Sunrise moves from 5:12 AM to 4:50 AM, and sunset from 6:33 PM to 6:55 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 13.4 | 13.4 | 13.4 | 13.4 | 13.5 | 13.5 | 13.5 | 13.6 | 13.6 | 13.6 | 13.6 | 13.7 | 13.7 | 13.7 | 13.8 | 13.8 | 13.8 | 13.8 | 13.9 | 13.9 | 13.9 | 13.9 | 13.9 | 14.0 | 14.0 | 14.0 | 14.0 | 14.0 | 14.1 | 14.1 | 14.1 |
| Sunrise (AM) | 5:12 | 5:11 | 5:10 | 5:09 | 5:08 | 5:07 | 5:06 | 5:05 | 5:04 | 5:03 | 5:02 | 5:01 | 5:00 | 5:00 | 4:59 | 4:58 | 4:57 | 4:57 | 4:56 | 4:55 | 4:55 | 4:54 | 4:53 | 4:53 | 4:52 | 4:52 | 4:51 | 4:51 | 4:50 | 4:50 | 4:50 |
| Sunset (PM) | 6:33 | 6:34 | 6:35 | 6:35 | 6:36 | 6:37 | 6:38 | 6:39 | 6:39 | 6:40 | 6:41 | 6:42 | 6:42 | 6:43 | 6:44 | 6:45 | 6:46 | 6:46 | 6:47 | 6:48 | 6:49 | 6:49 | 6:50 | 6:51 | 6:51 | 6:52 | 6:53 | 6:53 | 6:54 | 6:55 | 6:55 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 13.4 | 5:12 | 6:33 |
| 2 | 13.4 | 5:11 | 6:34 |
| 3 | 13.4 | 5:10 | 6:35 |
| 4 | 13.4 | 5:09 | 6:35 |
| 5 | 13.5 | 5:08 | 6:36 |
| 6 | 13.5 | 5:07 | 6:37 |
| 7 | 13.5 | 5:06 | 6:38 |
| 8 | 13.6 | 5:05 | 6:39 |
| 9 | 13.6 | 5:04 | 6:39 |
| 10 | 13.6 | 5:03 | 6:40 |
| 11 | 13.6 | 5:02 | 6:41 |
| 12 | 13.7 | 5:01 | 6:42 |
| 13 | 13.7 | 5:00 | 6:42 |
| 14 | 13.7 | 5:00 | 6:43 |
| 15 | 13.8 | 4:59 | 6:44 |
| 16 | 13.8 | 4:58 | 6:45 |
| 17 | 13.8 | 4:57 | 6:46 |
| 18 | 13.8 | 4:57 | 6:46 |
| 19 | 13.9 | 4:56 | 6:47 |
| 20 | 13.9 | 4:55 | 6:48 |
| 21 | 13.9 | 4:55 | 6:49 |
| 22 | 13.9 | 4:54 | 6:49 |
| 23 | 13.9 | 4:53 | 6:50 |
| 24 | 14.0 | 4:53 | 6:51 |
| 25 | 14.0 | 4:52 | 6:51 |
| 26 | 14.0 | 4:52 | 6:52 |
| 27 | 14.0 | 4:51 | 6:53 |
| 28 | 14.0 | 4:51 | 6:53 |
| 29 | 14.1 | 4:50 | 6:54 |
| 30 | 14.1 | 4:50 | 6:55 |
| 31 | 14.1 | 4:50 | 6:55 |
Solar energy in May
Average shortwave solar energy reaching the ground each day in May, about 7.6 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 — May's 7.6 kWh/m² sits near the top of that range.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 7.4 | 7.4 | 7.4 | 7.4 | 7.4 | 7.5 | 7.5 | 7.5 | 7.5 | 7.5 | 7.5 | 7.5 | 7.5 | 7.6 | 7.6 | 7.6 | 7.6 | 7.6 | 7.6 | 7.7 | 7.7 | 7.7 | 7.7 | 7.7 | 7.7 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 | 7.8 |
| Level | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 7.4 | Intense |
| 2 | 7.4 | Intense |
| 3 | 7.4 | Intense |
| 4 | 7.4 | Intense |
| 5 | 7.4 | Intense |
| 6 | 7.5 | Intense |
| 7 | 7.5 | Intense |
| 8 | 7.5 | Intense |
| 9 | 7.5 | Intense |
| 10 | 7.5 | Intense |
| 11 | 7.5 | Intense |
| 12 | 7.5 | Intense |
| 13 | 7.5 | Intense |
| 14 | 7.6 | Intense |
| 15 | 7.6 | Intense |
| 16 | 7.6 | Intense |
| 17 | 7.6 | Intense |
| 18 | 7.6 | Intense |
| 19 | 7.6 | Intense |
| 20 | 7.7 | Intense |
| 21 | 7.7 | Intense |
| 22 | 7.7 | Intense |
| 23 | 7.7 | Intense |
| 24 | 7.7 | Intense |
| 25 | 7.7 | Intense |
| 26 | 7.8 | Intense |
| 27 | 7.8 | Intense |
| 28 | 7.8 | Intense |
| 29 | 7.8 | Intense |
| 30 | 7.8 | Intense |
| 31 | 7.8 | Intense |
Is May a good time to visit Simi Valley?
Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
May is one of the better times to visit Simi Valley for general sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Simi Valley in May
From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In May, Simi Valley sees daytime highs around 73°F and nights near 55°F. Pack sun protection. Worth having: light clothes.
Sea temperature near Simi Valley in May
The nearest coast averages about 60°F in May — 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 58 | 58 | 58 | 58 | 60 | 63 | 66 | 67 | 67 | 65 | 62 | 60 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Cool | Cool | Cool | Cool | Cool | Cool | Cool | Cool |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 58 | Bracing |
| Feb | 58 | Bracing |
| Mar | 58 | Bracing |
| Apr | 58 | Bracing |
| May | 60 | Cool |
| Jun | 63 | Cool |
| Jul | 66 | Cool |
| Aug | 67 | Cool |
| Sep | 67 | Cool |
| Oct | 65 | Cool |
| Nov | 62 | Cool |
| Dec | 60 | Cool |
UV index in Simi Valley in May
Clear-sky midday UV in May 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 4 | 5 | 5 | 8 | 8 | 11 | 11 | 11 | 8 | 6 | 3 | 3 |
| Level | Moderate | Moderate | Moderate | Very high | Very high | Extreme | Extreme | Extreme | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 4 | Moderate |
| Feb | 5 | Moderate |
| Mar | 5 | Moderate |
| Apr | 8 | Very high |
| May | 8 | Very high |
| Jun | 11 | Extreme |
| Jul | 11 | Extreme |
| Aug | 11 | Extreme |
| Sep | 8 | Very high |
| Oct | 6 | High |
| Nov | 3 | Moderate |
| Dec | 3 | Moderate |
Air quality in Simi Valley in May
Average fine-particle pollution (PM2.5) through the year — so you can see where May 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 18 | 17 | 17 | 15 | 12 | 14 | 25 | 26 | 24 | 18 | 23 | 29 |
| Level | Moderate | Moderate | Moderate | Moderate | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 18 | Moderate |
| Feb | 17 | Moderate |
| Mar | 17 | Moderate |
| Apr | 15 | Moderate |
| May | 12 | Good |
| Jun | 14 | Moderate |
| Jul | 25 | Moderate |
| Aug | 26 | Moderate |
| Sep | 24 | Moderate |
| Oct | 18 | Moderate |
| Nov | 23 | Moderate |
| Dec | 29 | Moderate |
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.
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
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).