Met Office Hadley Centre observations datasets
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HadISD online material - preliminary version

Please read the Geoscientific Instrumentation, Methods & Data Systems and Climate of the Past I and II papers before using the material presented here.

The netCDF headers are listed below with some information as to what they contain.

Field NameLong NameUnits
timeTimeHours since 1-1-1931 00:00UT
input_station_idPrimary source for timestep data
wind gustm/s
slpsea-level pressurehPa
stnlpstation-level pressurehPa
past_sigwx1Past significant weather code
precip1_depthDepth of 1-hour precipitation accumulationmm
precip2_depthDepth of 2-hour precipitation accumulationmm
precip3_depthDepth of 3-hour precipitation accumulationmm
precip6_depthDepth of 6-hour precipitation accumulationmm
precip9_depthDepth of 9-hour precipitation accumulationmm
precip12_depthDepth of 12-hour precipitation accumulationmm
precip15_depthDepth of 15-hour precipitation accumulationmm
precip18_depthDepth of 18-hour precipitation accumulationmm
precip24_depthDepth of 24-hour precipitation accumulationmm
qc_flagsQuality control flags
flagged_valuesRemoved values (T, D, SLP, STNLP, WS, WD, TC, LC, MC, PP1, PP2, PP3, PP6, PP9, PP12, PP15, PP18, PP24)

The homogeneity information for this version is available here - the list of breaks and also some of the graphical outputs. The columns of the datafiles give the Station ID, the date of the change point, and two break magnitudes (one in the case of SLP). The first is from the monthly mean value, and the second is from the monthly mean diurnal range (temperature & dewpoint temperatures) or monthly mean daily maximum (wind speed). Missing values are denoted by -99.99. Please get in touch if there are any queries.

The inhomogeneity information has been calculated presuming the most recent period of a station is accurate and hence tranversing the timeseriers backwards in time. Therefore a negative in homogeneity value given indicates that prior to the month given, the data is at a lower value (so the adjustment required would be positive). Conversely, a positive vaue indicates that prior to the month given the data is at a higher value (a negative adjustment required).

DescriptionData fileNotes
Merged temperature inhomogeneitiesMergedBreaks_temperatures.dat
Merged dewpoint inhomogeneitiesMergedBreaks_dewpoints.dat
Merged SLP inhomogeneitiesMergedBreaks_slp.dat
Merged windspeeds inhomogeneitiesMergedBreaks_windspeeds.dat
And figures from the homogeneity assessment
Distribution - averagePHA_temperatures_average_distribution.pngPHA_dewpoints_average_distribution.pngPHA_slp_average_distribution.pngPHA_windspeeds_average_distribution.png
Distribution - DTRPHA_temperatures_dtr_distribution.pngPHA_dewpoints_dtr_distribution.png--
Distribution - max---PHA_windspeeds_max_distribution.png
Map - average - inhomogeneity sizebreak_size_map_temperatures_average.pngbreak_size_map_dewpoints_average.pngbreak_size_map_slp_average.pngbreak_size_map_windspeeds_average.png
Map - dtr - inhomogeneity sizebreak_size_map_temperatures_dtr.pngbreak_size_map_dewpoints_dtr.png--
Map - max - inhomogeneity size---break_size_map_windspeeds_max.png
Map - inhomogeneity numberbreak_number_map_temperatures.pngbreak_number_map_dewpoints.pngbreak_number_map_slp.pngbreak_number_map_windspeeds.png
Map - no inhomogeneitieszero_breaks_map_temperatures.pngzero_breaks_map_dewpoints.pngzero_breaks_map_slp.pngzero_breaks_map_windspeeds.png

A number of files and plots are linked below which were used or generated when creating HadISD.

DescriptionStation NumberData fileNotes
Station Lists
HadISD Station List8139hadisd_station_info_v310_2019f.txt1
HadISD Station List (with names)8139hadisd_station_fullinfo_v301_201901p.txt1
HadISD Station Additions195hadisd_station_additions_v301_201901p.txt
HadISD Station Removals159hadisd_station_removals_v301_201901p.txt
Composite Stations2104final_mergers.txt2
User Identified erroneous data
Failure Rate Summaries
Number of stations with a failures from a certain test in percentage binsall_fails_summary_20200107.dat3
Test 3-letter code descriptortests_codes.txt

Failure Rate Plots
Duplicate monthsAllpng
Odd ClusterTemperaturespng
Odd ClusterDew Pointspng
Odd ClusterSLPpng
Odd ClusterWind Speedpng
Frequent Value CheckTemperaturepng
Frequent ValuesDew pointpng
Frequent ValuesSLPpng
Diurnal Cycle CheckAllpng
Gap CheckTemperaturepng
Gap CheckDew pointpng
Gap CheckSLPpng
Record CheckTemperaturepng
Record CheckDew pointpng
Record CheckSLPpng
Record CheckWind speedpng
Day StringsTemperaturepng
Day StringsDew pointpng
Day StringsSLPpng
Day StringsWind speedpng
Straight StringsTemperaturepng
Straight StringsDew pointpng
Straight StringsSLPpng
Straight StringsWind speedpng
Hour StringsTemperaturepng
Hour StringsDew pointpng
Hour StringsSLPpng
Hour StringsWind speedpng
All temperature stringsTemperaturepng
All dewpoint stringsDew pointpng
All SLP stringsSLPpng
All wind stringsWind speedpng
Climatological CheckTemperaturepng
Climatological CheckDew pointpng
Climatological CheckSLPpng
Spike CheckTemperaturepng
Spike CheckDew pointpng
Spike CheckSLPpng
Spike CheckWind speedpng
SupersaturationDew pointpng
Dew point depressionDew pointpng
Dew point Cut OffDew pointpng
Variance CheckTemperaturepng
Variance CheckDew pointpng
Variance ChecksSLPpng
Variance ChecksWind speedpng
Logical CheckWind speedpng
Wind RoseWind speedpng
Cloud TotalLow,Mid,High,Totalpng
UnobservableHigh Cloudpng
UnobservableLow Cloudpng
UnobservableMid Cloudpng
UnobservableTotal Cloudpng
Full Low cloud checkMid & High Cloudpng
Full Mid cloud checkHigh Cloudpng
Negative cloud valueAll Cloudpng
Pressure Cross CheckStation Level Pressurepng
Neighbour OutlierTemperaturepng
Neighbour OutlierDew pointpng
Neighbour OutlierSLPpng
Month clearedTemperaturepng
Month clearedDew pointpng
Month clearedSLPpng
Month ClearedWind Speedpng
Month clearedWind Directionpng
Month clearedTotal cloudpng
Month clearedHigh Cloudpng
Month clearedMid Cloudpng
Month clearedLow Cloudpng
Month clearedCloud Basepng
AllDew pointpng


[1] Station ID, latitude, longitude and elevation used.
[2] First ID in the line is the station ID used throughout the processing. The remainder are ones which were composited into this station record.
[3] Summary table in the paper was created from this file. And you will need the test_codes.txt file to interpret these outputs.