howmuchsun

UV index and sunburn time in Geelong

UV peaks at 10.4 (very high) in January, around 13:30 local time. At that intensity, untanned skin of type III burns in about 23 min.

How long before you burn?

Sunburn after 23 min unprotected, at peak UV in January
Peak UV index 10.4 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 10.4 Very high 13:30 23 min
February 9.4 Very high 13:30 25 min
March 7.5 High 13:30 31 min
April 4.9 Moderate 12:30 48 min
May 2.9 Low 12:30 80 min
June 2.1 Low 12:30 111 min
July 2.3 Low 12:30 101 min
August 3.5 Moderate 12:30 66 min
September 5.6 Moderate 12:30 42 min
October 7.7 High 13:30 30 min
November 9.3 Very high 13:30 25 min
December 10.2 Very high 13:30 23 min

Burn time by skin type

At peak UV in January, with no sunscreen.

Fitzpatrick typeDescriptionBurns after
Type I Always burns, never tans 13 min
Type II Burns easily, tans minimally 16 min
Type III Burns moderately, tans gradually 23 min
Type IV Burns minimally, tans well 29 min
Type V Rarely burns, tans profusely 39 min
Type VI Never burns, deeply pigmented 64 min

UV through the day

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

none strongest

Other cities in Australia

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