howmuchsun

UV index and sunburn time in Tolyatti

UV peaks at 6.5 (high) in July, around 12:30 local time. At that intensity, untanned skin of type III burns in about 36 min.

How long before you burn?

Sunburn after 36 min unprotected, at peak UV in July
Peak UV index 6.5 High
With SPF 30 18 h if applied properly and reapplied

UV index month by month

Peak value on a representative day of each month, with burn time for skin type III.

MonthPeak UVCategoryPeak atBurns after
January 0.4 Low 12:30 568 min
February 1.1 Low 12:30 218 min
March 2.3 Low 12:30 101 min
April 4.1 Moderate 12:30 57 min
May 5.6 Moderate 12:30 41 min
June 6.5 High 12:30 36 min
July 6.5 High 12:30 36 min
August 5.5 Moderate 12:30 42 min
September 3.7 Moderate 12:30 63 min
October 1.8 Low 12:30 128 min
November 0.7 Low 12:30 352 min
December 0.3 Low 12:30 755 min

Burn time by skin type

At peak UV in July, with no sunscreen.

Fitzpatrick typeDescriptionBurns after
Type I Always burns, never tans 20 min
Type II Burns easily, tans minimally 26 min
Type III Burns moderately, tans gradually 36 min
Type IV Burns minimally, tans well 46 min
Type V Rarely burns, tans profusely 61 min
Type VI Never burns, deeply pigmented 102 min

UV through the day

UV index by month and hour in Europe/Samara local time, daylight saving included. Darker cells mean stronger UV.

UV index by month (rows) and local hour (columns). Each cell shows the rounded value; blank means zero.
Month456789101112131415161718192021
Jan
Feb 1 1 1 1
Mar 1 1 2 2 2 2 1 1
Apr 1 2 3 4 4 4 3 2 1 1
May 1 2 3 4 5 6 5 5 3 2 1
Jun 1 2 4 5 6 7 6 6 4 3 2 1
Jul 1 2 3 5 6 7 6 6 4 3 2 1
Aug 1 1 3 4 5 6 5 5 3 2 1
Sep 1 2 3 3 4 3 3 2 1
Oct 1 1 2 2 2 1 1
Nov 1 1 1
Dec

none strongest

Other cities in Russia

Assumptions

  • Clear sky. These are upper bounds. Cloud reduces UV, though less than people expect — you can burn on an overcast day.
  • No reflection. Snow roughly doubles your effective dose, and water and sand both add to it. None of that is modelled here.
  • Burn times are indicative. Published minimal erythemal doses vary by around 30% between studies, and individuals within a skin type vary more.
  • SPF assumes proper application. Most people apply a quarter of the amount used in testing, so real protection is far lower than the label.

Full methodology, sources and known limitations