Altadena, California, USA UV Index in April
The average UV index in Altadena, California, USA in April is about 7.6 (High), peaking near 10.5 at midday on clear days. Fair skin (Type II) can burn in roughly 12 minutes without sunscreen. SPF 30–50 sunscreen, a hat and sunglasses are essential. Seek shade between 11am and 3pm.
What is the UV index in Altadena, California, USA in April?
Average UV
7.6
High
Midday Peak
10.5
Clear-sky estimate
Fair Skin Burn Time
12 min
Type II, no sunscreen
How long can you stay in the sun in Altadena, California, USA in April?
| Skin type | Time to first burn | With SPF 30 |
|---|---|---|
| Type 1 | 8 min | up to 240 min |
| Type 2 | 12 min | up to 240 min |
| Type 3 | 20 min | up to 240 min |
| Type 4 | 32 min | up to 240 min |
| Type 5 | 47 min | up to 240 min |
| Type 6 | 71 min | up to 240 min |
Estimates based on Altadena, California, USA's latitude and typical April sun angle. Cloud cover, altitude and reflection from water or sand can raise or lower the real UV. Check the live forecast before long days outside.
Altadena, California, USA UV Index by Month
When is the UV index highest and lowest in Altadena, California, USA?
Highest: June (about 8). Lowest: December (about 5.6).
| Month | Average UV | Midday peak | Level | Fair skin burn |
|---|---|---|---|---|
| January | 5.8 | 8 | Moderate | 16 min |
| February | 6.4 | 8.8 | High | 14 min |
| March | 7.1 | 9.8 | High | 13 min |
| April | 7.6 | 10.5 | High | 12 min |
| May | 7.9 | 10.9 | High | 11 min |
| June | 8 | 11 | Very High | 11 min |
| July | 8 | 11 | Very High | 11 min |
| August | 7.8 | 10.7 | High | 12 min |
| September | 7.3 | 10 | High | 12 min |
| October | 6.7 | 9.2 | High | 13 min |
| November | 5.9 | 8.1 | Moderate | 15 min |
| December | 5.6 | 7.7 | Moderate | 16 min |
Common questions about UV in Altadena, California, USA in April
Do you need sunscreen in Altadena, California, USA in April?
Yes. A UV index of 7.6 is High, so use SPF 30+ on exposed skin between 10am and 4pm and reapply every two hours.
Can you tan in Altadena, California, USA in April?
Yes, UV of 7.6 is strong enough to tan. Fair skin can burn in about 12 minutes, so build exposure slowly and use sunscreen.
What time of day is UV strongest in Altadena, California, USA?
UV peaks around solar noon, roughly 11am to 2pm local time, when it can reach about 10.5 in April. Mornings and late afternoons are safest.
Is April a good month to visit Altadena, California, USA for the sun?
April averages UV 7.6, compared with a yearly high of 8 in June and a low of 5.6 in December. Darker skin (Type VI) can burn in about 71 minutes at this level.