howmuchsun

UV index and sunburn time in Maldonado

UV peaks at 10.9 (very high) in January, around 12:30 local time. At that intensity, untanned skin of type III burns in about 21 min.

How long before you burn?

Sunburn after 21 min unprotected, at peak UV in January
Peak UV index 10.9 Very high
With SPF 30 11 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 10.9 Very high 12:30 21 min
February 10.1 Very high 12:30 23 min
March 8.2 Very high 12:30 28 min
April 5.6 Moderate 12:30 41 min
May 3.6 Moderate 12:30 65 min
June 2.7 Low 12:30 87 min
July 2.9 Low 12:30 80 min
August 4.3 Moderate 12:30 55 min
September 6.5 High 12:30 36 min
October 8.6 Very high 12:30 27 min
November 10.2 Very high 12:30 23 min
December 10.9 Very high 12:30 21 min

Burn time by skin type

At peak UV in January, with no sunscreen.

Fitzpatrick typeDescriptionBurns after
Type I Always burns, never tans 12 min
Type II Burns easily, tans minimally 15 min
Type III Burns moderately, tans gradually 21 min
Type IV Burns minimally, tans well 27 min
Type V Rarely burns, tans profusely 37 min
Type VI Never burns, deeply pigmented 61 min

UV through the day

UV index by month and hour in America/Montevideo 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 1 3 5 8 10 11 11 9 7 4 2
Feb 2 4 7 9 10 10 8 6 3 1
Mar 1 3 5 7 8 8 7 4 2 1
Apr 1 2 4 5 6 5 4 2 1
May 1 2 3 4 3 2 1
Jun 1 1 2 3 2 2 1
Jul 1 2 2 3 3 2 1
Aug 1 2 4 4 4 3 2 1
Sep 1 3 4 6 6 6 5 3 1
Oct 1 2 4 6 8 9 8 6 4 2 1
Nov 1 3 6 8 10 10 9 7 5 3 1
Dec 1 3 6 8 10 11 10 9 6 4 2

none strongest

Other cities in Uruguay

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