Daily Temperature and Precipitation Data for 223 Former-USSR Stations

This 223-station database contains four variables: daily mean, minimum, and maximum temperature, and daily total precipitation (liquid equivalent). Temperature were taken three times a day from 1881-1935, four times a day from 1936-65, and eight times a day since 1966. Daily mean temperature is defined as the average of all observations for each calendar day. Daily maximum/minimum temperatures are derived from maximum/minimum thermometer measurements. See the measurement description file for further details. Daily precipitation totals are also available (to the nearest tenth of a millimeter) for each station. Throughout the record, daily precipitation is defined as the total amount of precipitation recorded during a 24-h period, snowfall being converted to a liquid total by melting the snow in the gauge. From 1936 on, rain gauges were checked several times each day; the cumulative total of all observations during a calendar day was presumably used as the daily total. This version of differs from the previous version as follows:

 

·        The coding of the group quality flag for air temperature indices has changed

·        The record format of the data files has changed

·        The dataset has been updated with data for 1996-2001 and partially for 1993-1995

·        Additional data errors have been corrected

 

 

Data Format

Table 1. Format of Data Files

 

 

Field number

Position

Field

length

Field contents

Note

1

2-6

5

WMO station number

 

7-8

2

Blank

 

2

9-12

4

Year

 

 

13-14

2 

Blank

 

3

15-16

2

Month

 

 

17-18

2

Blank

 

4

19-20

2

Day

 

 

21

1

Blank

 

 

5

22

1

TFLAG, group quality flag for air temperature indices

 

See Table 2

 

23

1

Blank

 

6

24-28

5

TMIN, minimum daily air temperature

In degrees Celsius to an accuracy of

0.1 degree

 

29

1

Blank

 

7

30

1

QTMIN, quality flag for TMIN

See Table 3

 

31

1

Blank

 

8

32-36

5

TMID, mean daily air temperature

In degrees Celsius to an accuracy of

0.1 degree  

 

37

1

Blank

 

9

38

1

QTMID, quality flag for TMID

See Table 3

 

39

1

Blank

 

10

40-44

5

TMAX, maximum daily air temperature

In degrees Celsius to an accuracy of

0.1 degree   

 

45

1

Blank

 

11

46

1

QTMAX, quality flag for TMAX

See Table 3

 

47

1

Blank

 

12

48-52

5

R, daily precipitation total  

In millimeters to an accuracy of

0.1 mm

 

53

1

Blank

 

13

54

1

CR, Compliment flag for R

See Table 4

 

55

1

Blank

 

14

56

1

QR, quality flag for R

See Table 3

 

57

1

Blank

 

15

58-61

4

DATA_FLAGS, flags of record fields’ state

See Table 5

 

 

Table 2. Values of TFLAG

 

 

TFLAG

 

0

if tmin,tmid are absent;

if tmin,tmax are absent;

if tmid,tmax are absent.

if tmin <= tmid <= tmax;

if tmin <= tmax and tmid is absent;

if tmin <= tmid and tmax is absent;

if tmid <= tmax and tmin is absent;

1

 if tmin < tmax <= tmid;

 if tmid <= tmin < tmax;

 if tmid <= tmax < tmin;

 if tmax < tmin <= tmid;

 if tmax <= tmid < tmin;

 if tmid < tmin and tmax is absent;

 if tmax < tmin and tmid is absent;

 if tmax < tmid and tmin is absent;

 if tmin,tmid,tmax are absent;

9

if tmax,tmid,tmax are absent

 

 

Table 3. Values of QTMIN, QTMID, QTMAX, and QR

 

 

 

QTMIN, QTMID, QTMAX,QR

 

0

 valid value

2

suspect value

9

rejected value or observation was not made.

With quality flag=9 the elements field is filled

with '9' in all field positions

 

Table 4. Values of CR

 

 

CR

 

0

precipitation is 0.1 mm or greater

1

precipitation was accumulated over several days

2

observations were made but there was no precipitation.

In this case R = 0

3

small precipitation amount (< 0.1 mm).

In this case R = 0

 

Table 5. Values of DATA_FLAGS

 

 

DATA_FLAGS

Value of DATA_FLAGS

AAAA

Flags for data values new to this version of the dataset .

(the character “A” originates from the English word “ADD”)

O

This character may be present in DATA_FLAGS in any position (the character “O” originates from the English word “OLD”):

Position 1 – the value  T_MIN remains unchanged compared with the previous version of the data set;

Position 2 – the value  T_MID remains unchanged compared with the previous version of the data set;

Position 3 – the value  T_MAX remains unchanged compared with the previous version of the data set;

Position 4 – the value R remains unchanged compared with the previous version of the data set.

R

This character may be present in DATA_FLAGS in any position (the character “R” originates from the English word “Replace”):

Position 1 – the value T_MIN is replaced in this release by a new value;

Position 2 – the value T_MID is replaced in this release by a new value;

position 3 – the value T_MAX is replaced in this release by a new value;

Position 4 – the value R is replaced in this release by a new value.