The Maproom explores historical daily temperature by calculating simple seasonal statistics.

Many options can be specified to produce yearly time series of a chosen seasonal diagnostic of the daily temperature data. The user can then choose to map the mean, standard deviation or probability of exceeding a chosen threshold, over years; clicking on the map will then produce a local yearly time series of the chosen diagnostic.

**Years and Season**:
Specify the range of years over which to perform the analysis, and choose the start
and end dates of the season over which the diagnostics are to be performed.

**Seasonal Data Coverage**:
A minimum fraction of non-missing days per season can be required in order for the
seasonal diagnostic to be defined at that station — if this minimum threshold is not
met, then the seasonal diagnostic is assigned a missing value at that station, for
that season and year.

**Hot/Cold Day Definition**:
This threshold is used to define in Celsius degrees (non inclusive) the temperature
under which a day is considered cold if the minimum temperature is below it; or the
temperature above which a days is considered hot if the maximum temperature is above
it; or the reference temperature for to compute the heating degree days.
**Seasonal daily statistics**: Choose the seasonal diagnostic quantity (i.e., the statistic of the daily data)
to be computed for each season, from the following choices.
**Minimum and Maximum Temperature**: average minimum or maximum daily temperature over the season.
**Heating Degree Days**: Heating degree days are summations of negative differences between the mean daily
temperature and user-defined reference base temperature during the season. The mean
temperature is defined as the average of the minimum and the maximum.
**Number of Cold and Hot days**:
the number of cold or hot days during the season according to the user-defined threshold
and according respectively to the minumim temperature and the maximum temperature.

**Yearly seasonal statistics**: a choice of yearly statistics over the chosen season of the selected range of years
to produce the map among: the mean, the standard deviation and the probability of
exceeding a user specified threshold.

**Data**: Daily minimum and maximum temperature from GSOD station data.

Contact help@iri.columbia.edu with any technical questions or problems with this Map Room.