Climate data De Bilt; temperature, precipitation, sunshine 1800-2014

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)
Climate 1971 to 2000 9.8 3.3 16.6 0.4 21.4 8 58 22 3 3,075 827 131 25 109 65 543 82 1,524 76
Climate 1981 to 2010 10.1 3.4 17.0 0.5 21.9 8 58 26 4 2,884 887 131 25 122 63 559 82 1,602 61
2009 10.5 2.2 17.4 -0.6 22.4 9 56 27 1 2,805 833 132 28 132 88 612 81 1,838 37
2010 9.1 1.1 17.7 -1.5 22.7 29 89 27 3 3,321 901 123 58 126 100 590 80 1,752 62
2011 10.9 2.3 16.3 -0.5 20.6 4 50 20 1 2,622 962 127 9 147 98 585 81 1,788 48
2012 10.3 4.1 16.9 1.1 21.4 13 50 24 2 2,879 973 140 10 120 88 564 81 1,610 48
2013 9.8 2.9 17.5 0.4 22.5 13 69 27 7 3,078 934 139 32 139 85 565 80 1,628 57
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.
Explanation of symbols

Table description


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.