Federal Meteorological Handbook No.1
12-17
overcast layer of stratus clouds; a report of "8/903" would indicate cumulonimbus
type low clouds, no middle clouds, and dense cirrus high clouds.
c) Duration of Sunshine (98mmm). The duration of sunshine that occurred the
previous calendar day shall be coded in the 0800 UTC report. If the station is
closed at 0800 UTC, the group shall be coded in the first 6-hourly METAR after
the station opens. The duration of sunshine shall be coded in the format,
98mmm, where 98 is the group indicator and mmm is the total minutes of
sunshine. The minutes of sunshine shall be coded by using the hundreds, tens,
and units digits. For example, 96 minutes of sunshine would be coded "98096". If
no sunshine occurred, the group would be coded "98000".
d) Hourly Temperature and Dew Point (TsnT'T'T'snT'dT'dT'd). At designated
stations, the hourly temperature and dew point group shall be coded to the tenth
of a degree Celsius in the format, TsnT'T'T'snT'dT'dT'd, where T is the group
indicator, sn is the sign of the temperature, T'T'T' is the temperature, and
T'dT'dT'd is the dew point (see paragraphs 10.5.1 and 10.5.3). The sign of the
temperature and dew point shall be coded as 1 if the value is below 0°C and 0 if
the value is 0°C or higher. The temperature and dew point shall be reported in
tens, units, and tenths of degrees Celsius. There shall be no spaces between the
entries. For example, a temperature of 2.6°C and dew point of -1.5°C would be
reported in the body of the report as "03/M01" and the TsnT'T'T'snT'dT'dT'd
group as "T00261015". If dew point is missing report the temperature; if the
temperature is missing do not report the temperature/dew point group.
e) 6-Hourly Maximum Temperature (1s
n
T
x
T
x
T
x
). At designated stations, the 6-
hourly maximum temperature group shall be coded in the format, 1s
n
T
x
T
x
T
x
,
where 1 is the group indicator, s
n
is the sign of the temperature, T
x
T
x
T
x
is the
maximum temperature in tenths of degrees Celsius using three digits (see
paragraphs 10.4.4, 10.5.2, and 10.5.3). The sign of the maximum temperature
shall be coded as 1 if the maximum temperature is below 0°C and 0 if the
maximum temperature is 0°C or higher. For example, a maximum temperature of
-2.1°C would be coded "11021"; 14.2°C would be coded "10142".
f) 6-Hourly Minimum Temperature (2s
n
T
n
T
n
T
n
). At designated stations, the 6-
hourly minimum temperature group shall be coded in the format, 2s
n
T
n
T
n
T
n
,
where 2 is the group indicator, s
n
is the sign of the temperature, and T
n
T
n
T
n
is
the minimum temperature in tenths of degrees Celsius using three digits (see
paragraphs 10.4.4, 10.5.2, and 10.5.3). The sign of the minimum temperature
shall be coded as 1 if the minimum temperature is below 0°C and 0 if the
minimum temperature is 0°C or higher. For example, a minimum temperature of -
0.1°C would be coded "21001"; 1.2°C would be coded "20012".
g) 24-Hour Maximum and Minimum Temperature (4s
n
T
x
T
x
T
x
s
n
T
n
T
n
T
n
). At
designated stations, the 24-hour maximum temperature and the 24-hour
minimum temperature shall be coded in the format, 4s
n
T
x
T
x
T
x
s
n
T
n
T
n
T
n
, where 4
is the group indicator, s
n
is the sign of the temperature, T
x
T
x
T
x
is the maximum
24-hour temperature, and T
n
T
n
T
n
is the 24-hour minimum temperature (see
paragraphs 10.4.4, 10.5.2, and 10.5.3). T
x
T
x
T
x
and T
n
T
n
T
n
shall be coded in
tenths of degrees Celsius using three digits. The sign of the maximum or
minimum temperature shall be coded as 1 if it is below 0°C and 0 if it is 0°C or