Nagano, Japan UV Index in August
The average UV index in Nagano, Japan in August is about 5.8 (Moderate), peaking near 9.7 at midday on clear days. Fair skin (Type II) can burn in roughly 16 minutes without sunscreen. Wear SPF 30+ sunscreen if you are outside for more than an hour, especially near water or sand.
What is the UV index in Nagano, Japan in August?
Average UV
5.8
Moderate
Midday Peak
9.7
Clear-sky estimate
Fair Skin Burn Time
16 min
Type II, no sunscreen
How long can you stay in the sun in Nagano, Japan in August?
| Skin type | Time to first burn | With SPF 30 |
|---|---|---|
| Type 1 | 10 min | up to 240 min |
| Type 2 | 16 min | up to 240 min |
| Type 3 | 26 min | up to 240 min |
| Type 4 | 41 min | up to 240 min |
| Type 5 | 62 min | up to 240 min |
| Type 6 | 93 min | up to 240 min |
Estimates based on Nagano, Japan's latitude and typical August 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.
When is the UV index highest and lowest in Nagano, Japan?
Highest: June (about 6). Lowest: December (about 4).
| Month | Average UV | Midday peak | Level | Fair skin burn |
|---|---|---|---|---|
| January | 4.2 | 7 | Moderate | 21 min |
| February | 4.7 | 7.8 | Moderate | 19 min |
| March | 5.2 | 8.7 | Moderate | 17 min |
| April | 5.7 | 9.5 | Moderate | 16 min |
| May | 5.9 | 9.8 | Moderate | 15 min |
| June | 6 | 10 | High | 15 min |
| July | 6 | 10 | High | 15 min |
| August | 5.8 | 9.7 | Moderate | 16 min |
| September | 5.4 | 9 | Moderate | 17 min |
| October | 4.9 | 8.2 | Moderate | 18 min |
| November | 4.3 | 7.2 | Moderate | 21 min |
| December | 4 | 6.7 | Moderate | 23 min |
Common questions about UV in Nagano, Japan in August
Do you need sunscreen in Nagano, Japan in August?
Yes. A UV index of 5.8 is Moderate, so use SPF 30+ on exposed skin between 10am and 4pm and reapply every two hours.
Can you tan in Nagano, Japan in August?
Yes, UV of 5.8 is strong enough to tan. Fair skin can burn in about 16 minutes, so build exposure slowly and use sunscreen.
What time of day is UV strongest in Nagano, Japan?
UV peaks around solar noon, roughly 11am to 2pm local time, when it can reach about 9.7 in August. Mornings and late afternoons are safest.
Is August a good month to visit Nagano, Japan for the sun?
August averages UV 5.8, compared with a yearly high of 6 in June and a low of 4 in December. Darker skin (Type VI) can burn in about 93 minutes at this level.