Climate data De Bilt; temperature, precipitation, sunshine 1800-2014
| Periods | Temperature Year average (degree Celsius) | Temperature Winter average (degree Celsius) | Temperature Summer average (degree Celsius) | Temperature Winter average minimum temperature (degree Celsius) | Temperature Summer average maximum temperature (degree Celsius) | Temperature Ice days (days) | Temperature Frost days (days) | Temperature Summery days (days) | Temperature Tropical days (days) | Temperature Heating degree days (degree Celsius) | Precipitation Quantity of precipitation (mm) | Precipitation Days with precipitation (days) | Precipitation Snow days (days) | Precipitation Dry days (days) | Precipitation Days with fog (days) | Precipitation Evaporation (mm) | Precipitation Relative humidity (%) | Sunshine Hours of sunshine (hours) | Sunshine Sunless days (days) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2014 | 11.7 | 6.0 | 17.4 | 3.3 | 22.0 | 0 | 26 | 23 | 2 | 2,385 | 952 | 124 | 3 | 130 | 88 | 607 | 81 | 1,787 | 42 |
| Source: CBS. | |||||||||||||||||||
Table explanation
This table presents climate data from the Dutch weather station De Bilt (source: KNMI).
The average winter and summer temperatures, which started in 1800, are the longest current series shown in the table.
The series on the average year temperature and on hours of sunshine per year started in 1900. For the number of days below of above a certain temperature (ice days, summery days) the ranges started between 1940 and 1950. The complete set of climate data is available from 1980 onwards.
Data available from: 1800-2014.
Status of the figures:
All data are definite.
Changes as of 19 April 2016:
Not. This table has been discontinued.
When will new figures be published?
Not applicable anymore.
Data on the weather and climate in The Netherlands can be found on the website of the Royal Netherlands Meteorological Institute KNMI
Description topics
- Temperature
- Air temperature in degrees Celsius.
- Year average
- The average of daily recorded temperatures for the whole year.
- Winter average
- The average of daily recorded temperatures in the winter, i.e. from December to February. The average therefore includes one month of the previous year.
- Summer average
- The average of daily recorded temperatures in the summer, i.e. June to August
- Winter average minimum temperature
- The average of the lowest temperature of each day in the winter, i.e. from December to February. The average therefore includes one month of the previous year.
- Summer average maximum temperature
- The average of the highest temperature of each day in the summer, i.e. from June to August.
- Ice days
- Number of days in the year with a maximum temperature below 0.0 degrees Celsius
- Frost days
- Number of days in the year with a minimum temperature below 0.0 degrees Celsius
- Summery days
- Number of days in the year with a maximum temperature of 25.0 degrees Celsius or higher.
- Tropical days
- Number of days in the year with a maximum temperature of 30.0 degrees Celsius or higher.
- Heating degree days
- Heating degree days (HDD):
The sum per year of average daily temperatures below 18 degrees Celsius.
For example:
-a day with an average temperature of 20 degrees Celsius: no HDD
-a day with an average temperature of 10 degrees Celsius: 18-10 = 8 HDD
-a day with an average temperature of -4 degrees Celsius: 18 - (- 4) = 22 HDD
The sum of these three days is thus 30 heating degree days .
- Precipitation
- Includes rain, snow, hail, sleet, dew and frost.
- Quantity of precipitation
- The quantity of precipitation per day is the number of mm that falls between 8.00 hrs in the morning and 8.00 hrs the following morning, Measured with a pluviometer.
- Days with precipitation
- The number of days with at least 1.0 mm precipitation
- Snow days
- A day on which at least one snow flake has been observed.
- Dry days
- Day without measurable precipitation.
- Days with fog
- Days on which visibility is less than 1,000 metres at some time.
- Evaporation
- Transition of liquid water (in soil and plants) into vapour, Calculated from the average day temperature and solar radiation.
- Relative humidity
- The ratio of the pressure of water vapour in the atmosphere to the saturated vapour pressure of water at that temperature, measured at a height of 1.5 metres above the ground.
- Sunshine
- Radiation of the sun (=global radiation). The duration of sunshine is calculated from the global radiation.
- Hours of sunshine
- The duration of the sunshine in hours. Until 1992 this was measured with a Campbell-Stokes sunshine meter. The instrument consists of a crystal ball, which works as a burning glass. Since 1992 sunshine has been measured electronically with a pyranometer. Values above approximately 120 Watt/m2 are registered as sunshine. This more or less corresponds with a situation in which the sun generates shadows.
- Sunless days
- Days with zero hours of sunshine.