Harpenden (Hertfordshire) weather

This shows the highest wind speed that you should encounter today.

Feels like temperature considers factors such as wind speed and humidity. This gives you a better idea of how the temperature will actually feel.

This shows when the next chance of rain or other precipitation is.

Humidity is the amount of water vapor in the air. If there is a lot of water vapour, the humidity will be high. The higher the percentage of humidity, the wetter it will feel outside.

UV exposure index and the protection required to help keep you safe:

- No risk of UV
It’s safe to stay outside. 1-2 Low
You can safely stay outside. Consider sunscreen in direct sunlight. 3-5 Moderate
Take care during midday hours and do not spend too much time in the sun unprotected. Sunscreen advised. 6-7 High
Seek shade during midday hours, cover up and wear sunscreen. 8-10 Very high
Spend time in the shade between 11am and 3pm. Shirt, sunscreen and hat are essential. 11 Extreme
Avoid being outside during midday hours. Shirt, sunscreen and hat essential.

Visibility measures the distance at which an object can be clearly seen.

Sunrise or sunset is the moment when the top of the sun’s orb is level with the horizon. This would be when looking at it from sea level with nothing in the way and with perfect conditions.

This shows the average air pollution levels for regions of the country. This can be from pollutants such as sulphur dioxide, nitrogen oxides, and particulate matter. The data is taken from Defra’s 'Daily Air Quality Index'.

There is advice if you are at risk from higher levels of pollution.

This shows the pollen level for the region this location is in. More information about regions is on our pollen forecast page.

The forecast uses 4 levels:

• Low
• Moderate
• High
• Very high

This shows the highest wind speed that you should encounter today.

Feels like temperature considers factors such as wind speed and humidity. This gives you a better idea of how the temperature will actually feel.

This shows when the next chance of rain or other precipitation is.

Humidity is the amount of water vapor in the air. If there is a lot of water vapour, the humidity will be high. The higher the percentage of humidity, the wetter it will feel outside.

UV exposure index and the protection required to help keep you safe:

- No risk of UV
It’s safe to stay outside. 1-2 Low
You can safely stay outside. Consider sunscreen in direct sunlight. 3-5 Moderate
Take care during midday hours and do not spend too much time in the sun unprotected. Sunscreen advised. 6-7 High
Seek shade during midday hours, cover up and wear sunscreen. 8-10 Very high
Spend time in the shade between 11am and 3pm. Shirt, sunscreen and hat are essential. 11 Extreme
Avoid being outside during midday hours. Shirt, sunscreen and hat essential.

Visibility measures the distance at which an object can be clearly seen.

Sunrise or sunset is the moment when the top of the sun’s orb is level with the horizon. This would be when looking at it from sea level with nothing in the way and with perfect conditions.

This shows the average air pollution levels for regions of the country. This can be from pollutants such as sulphur dioxide, nitrogen oxides, and particulate matter. The data is taken from Defra’s 'Daily Air Quality Index'.

There is advice if you are at risk from higher levels of pollution.

This shows the pollen level for the region this location is in. More information about regions is on our pollen forecast page.

The forecast uses 4 levels:

• Low
• Moderate
• High
• Very high

This shows the highest wind speed that you should encounter today.

Feels like temperature considers factors such as wind speed and humidity. This gives you a better idea of how the temperature will actually feel.

This shows when the next chance of rain or other precipitation is.

Humidity is the amount of water vapor in the air. If there is a lot of water vapour, the humidity will be high. The higher the percentage of humidity, the wetter it will feel outside.

UV exposure index and the protection required to help keep you safe:

- No risk of UV
It’s safe to stay outside. 1-2 Low
You can safely stay outside. Consider sunscreen in direct sunlight. 3-5 Moderate
Take care during midday hours and do not spend too much time in the sun unprotected. Sunscreen advised. 6-7 High
Seek shade during midday hours, cover up and wear sunscreen. 8-10 Very high
Spend time in the shade between 11am and 3pm. Shirt, sunscreen and hat are essential. 11 Extreme
Avoid being outside during midday hours. Shirt, sunscreen and hat essential.

Visibility measures the distance at which an object can be clearly seen.

Sunrise or sunset is the moment when the top of the sun’s orb is level with the horizon. This would be when looking at it from sea level with nothing in the way and with perfect conditions.

This shows the average air pollution levels for regions of the country. This can be from pollutants such as sulphur dioxide, nitrogen oxides, and particulate matter. The data is taken from Defra’s 'Daily Air Quality Index'.

There is advice if you are at risk from higher levels of pollution.

This shows the pollen level for the region this location is in. More information about regions is on our pollen forecast page.

The forecast uses 4 levels:

• Low
• Moderate
• High
• Very high

This shows the highest wind speed that you should encounter today.

Feels like temperature considers factors such as wind speed and humidity. This gives you a better idea of how the temperature will actually feel.

This shows when the next chance of rain or other precipitation is.

Humidity is the amount of water vapor in the air. If there is a lot of water vapour, the humidity will be high. The higher the percentage of humidity, the wetter it will feel outside.

UV exposure index and the protection required to help keep you safe:

- No risk of UV
It’s safe to stay outside. 1-2 Low
You can safely stay outside. Consider sunscreen in direct sunlight. 3-5 Moderate
Take care during midday hours and do not spend too much time in the sun unprotected. Sunscreen advised. 6-7 High
Seek shade during midday hours, cover up and wear sunscreen. 8-10 Very high
Spend time in the shade between 11am and 3pm. Shirt, sunscreen and hat are essential. 11 Extreme
Avoid being outside during midday hours. Shirt, sunscreen and hat essential.

Visibility measures the distance at which an object can be clearly seen.

Sunrise or sunset is the moment when the top of the sun’s orb is level with the horizon. This would be when looking at it from sea level with nothing in the way and with perfect conditions.

This shows the average air pollution levels for regions of the country. This can be from pollutants such as sulphur dioxide, nitrogen oxides, and particulate matter. The data is taken from Defra’s 'Daily Air Quality Index'.

There is advice if you are at risk from higher levels of pollution.

This shows the pollen level for the region this location is in. More information about regions is on our pollen forecast page.

The forecast uses 4 levels:

• Low
• Moderate
• High
• Very high

This shows the highest wind speed that you should encounter today.

Feels like temperature considers factors such as wind speed and humidity. This gives you a better idea of how the temperature will actually feel.

This shows when the next chance of rain or other precipitation is.

Humidity is the amount of water vapor in the air. If there is a lot of water vapour, the humidity will be high. The higher the percentage of humidity, the wetter it will feel outside.

UV exposure index and the protection required to help keep you safe:

- No risk of UV
It’s safe to stay outside. 1-2 Low
You can safely stay outside. Consider sunscreen in direct sunlight. 3-5 Moderate
Take care during midday hours and do not spend too much time in the sun unprotected. Sunscreen advised. 6-7 High
Seek shade during midday hours, cover up and wear sunscreen. 8-10 Very high
Spend time in the shade between 11am and 3pm. Shirt, sunscreen and hat are essential. 11 Extreme
Avoid being outside during midday hours. Shirt, sunscreen and hat essential.

Visibility measures the distance at which an object can be clearly seen.

Sunrise or sunset is the moment when the top of the sun’s orb is level with the horizon. This would be when looking at it from sea level with nothing in the way and with perfect conditions.

This shows the average air pollution levels for regions of the country. This can be from pollutants such as sulphur dioxide, nitrogen oxides, and particulate matter. The data is taken from Defra’s 'Daily Air Quality Index'.

There is advice if you are at risk from higher levels of pollution.

This shows the pollen level for the region this location is in. More information about regions is on our pollen forecast page.

The forecast uses 4 levels:

• Low
• Moderate
• High
• Very high

This shows the highest wind speed that you should encounter today.

Feels like temperature considers factors such as wind speed and humidity. This gives you a better idea of how the temperature will actually feel.

This shows when the next chance of rain or other precipitation is.

Humidity is the amount of water vapor in the air. If there is a lot of water vapour, the humidity will be high. The higher the percentage of humidity, the wetter it will feel outside.

UV exposure index and the protection required to help keep you safe:

- No risk of UV
It’s safe to stay outside. 1-2 Low
You can safely stay outside. Consider sunscreen in direct sunlight. 3-5 Moderate
Take care during midday hours and do not spend too much time in the sun unprotected. Sunscreen advised. 6-7 High
Seek shade during midday hours, cover up and wear sunscreen. 8-10 Very high
Spend time in the shade between 11am and 3pm. Shirt, sunscreen and hat are essential. 11 Extreme
Avoid being outside during midday hours. Shirt, sunscreen and hat essential.

Visibility measures the distance at which an object can be clearly seen.

Sunrise or sunset is the moment when the top of the sun’s orb is level with the horizon. This would be when looking at it from sea level with nothing in the way and with perfect conditions.

This shows the average air pollution levels for regions of the country. This can be from pollutants such as sulphur dioxide, nitrogen oxides, and particulate matter. The data is taken from Defra’s 'Daily Air Quality Index'.

There is advice if you are at risk from higher levels of pollution.

This shows the highest wind speed that you should encounter today.

Feels like temperature considers factors such as wind speed and humidity. This gives you a better idea of how the temperature will actually feel.

This shows when the next chance of rain or other precipitation is.

Humidity is the amount of water vapor in the air. If there is a lot of water vapour, the humidity will be high. The higher the percentage of humidity, the wetter it will feel outside.

UV exposure index and the protection required to help keep you safe:

- No risk of UV
It’s safe to stay outside. 1-2 Low
You can safely stay outside. Consider sunscreen in direct sunlight. 3-5 Moderate
Take care during midday hours and do not spend too much time in the sun unprotected. Sunscreen advised. 6-7 High
Seek shade during midday hours, cover up and wear sunscreen. 8-10 Very high
Spend time in the shade between 11am and 3pm. Shirt, sunscreen and hat are essential. 11 Extreme
Avoid being outside during midday hours. Shirt, sunscreen and hat essential.

Visibility measures the distance at which an object can be clearly seen.

Sunrise or sunset is the moment when the top of the sun’s orb is level with the horizon. This would be when looking at it from sea level with nothing in the way and with perfect conditions.

This shows the average air pollution levels for regions of the country. This can be from pollutants such as sulphur dioxide, nitrogen oxides, and particulate matter. The data is taken from Defra’s 'Daily Air Quality Index'.

There is advice if you are at risk from higher levels of pollution.