UV index

Access UV index (Clear Sky) for any location on Earth! Data is available in JSON.

Current UV Index for one location

Description:
Call UV Index for current data for specific location (lat/lon).
API call:
http://api.owm.io/air/1.0/uvi/current?lat={lat}&lon={lon}&appid={API key}
Parameters:
lat, lon coordinates of the location of your interest
Examples of API calls:

http://api.owm.io/air/1.0/uvi/current?lat=55&lon=37

API respond:
{"coord":[36.75,54.75],"dt":1446595200,"value":0.87}
Parameters of API respond:
  • coord coordinates, lon, lat (internal parameter just for self-checking, we will remove it)
  • dt Date, unix, UTC
  • value UV index measured when the sun noon on condition that the sky is clear


Historical UV Index for one location

Description:
Call historical UV Index for specific location (lat/lon).
API call:
http://api.owm.io/air/1.0/uvi/list?lat={lat}&lon={lon}&from={start}&to={end}&appid={API key}
Parameters:

lat, lon coordinates of the location of your interest

from start date (unix time, UTC time zone), e.g. start=1369728000

to end date (unix time, UTC time zone), e.g. end=1369789200

Examples of API calls:

http://api.owm.io/air/1.0/uvi/list?lat=55&lon=37&from=1446465600&to=1446595200

API respond:
{"coord":[36.75,54.75],
"data":[
    {"dt":1446465600,"value":0.87},
    {"dt":1446595200,"value":0.87}
    ]}
Parameters of API respond:
  • coord coordinates, lon, lat (internal parameter just for self-checking, we will remove it)
  • data list of data
    • data.dt Date, unix, UTC
    • data.value UV index measured when the sun noon on condition that the sky is clear



How to use the UV index

UV Index Media graphic color Risk of harm from unprotected sun exposure, for the average adult Recommended protection
0–2.9 Green Low Wear sunglasses on bright days; use sunscreen if there is snow on the ground, which reflects UV radiation, or if you have particularly fair skin.
3–5.9 Yellow Moderate Take precautions, such as covering up, if you will be outside. Stay in shade near midday when the sun is strongest.
6–7.9 Orange High Cover the body with sun protective clothing, use SPF 30+ sunscreen, wear a hat, reduce time in the sun within three hours of solar noon, and wear sunglasses.
8–10.9 Red Very high Wear SPF 30+ sunscreen, a shirt, sunglasses, and a wide-brimmed hat. Do not stay in the sun for too long.
11+ Violet Extreme Take all precautions: Wear SPF 30+ sunscreen, a long-sleeved shirt and trousers, sunglasses, and a very broad hat. Avoid the sun within three hours of solar noon.

When interpreting the UV Index and recommendations, be aware that:
  • The intensity of UV radiation reaching the surface of the earth depends on the angle of the sun in the sky. Each day, the sun achieves its highest angle (highest intensity, shortest shadows) at solar noon, which only approximately corresponds to 12:00 on clocks. This is because of the differences between solar time and local time in a given time zone. In general, UV risk is high when the sun is directly enough overhead that people's shadows are shorter than their height.
  • Likewise, UV intensity can be higher or lower for surfaces at different angles to the horizontal. For example, if people are walking or standing outdoors, UV exposure to the eyes and vertical surfaces of skin, such as the face, can actually be more severe when the sun is lower such as the end of a summer's day, or winter afternoons on a ski trail. This is partly a consequence of the fact that the measurement equipment upon which the index is based is a flat horizontal surface.
  • UV intensity can nearly double with reflection from snow or other bright surfaces like water, sand, or concrete.
  • The recommendations given are for average adults with lightly tan skin. Those with darker skin are more likely to withstand greater sun exposure, while extra precautions are needed for children, seniors, particularly fair-skinned adults, and those who have greater sun sensitivity for medical reasons or from UV exposure in previous days. (The skin's recovery from UV radiation generally takes two days or more to run its course.)
  • Because of the way the UV Index is calculated, it technically expresses the risk of developing sunburn, which is caused mostly by UV radiation. However, UV radiation also causes damage (photoaging, melanoma). Under some conditions, including most tanning beds, the UVA level may be disproportionately higher than described by the UV Index. The use of broad-spectrum (UVA/UVB) sunscreen can help address this concern.