The ESRL website will be unavailable for 24 hours starting Friday, March 6th at 5:00pm MT due to building maintenance.
 

Plot Description

Daily mean maximum daily temperature and extremes

The plot shows the average and the extremes of the daily maximum temperature for each day of the year averaged over 30 years. The middle line is the average daily temperature for that day which computed by taking the average over all available years for that day. The top line is the highest maximum temperature for that day over 30 years. The lower line is the lowest maximum temperature over all available years. The last two represent the range of maximum temperatures possible for that day (hence "extremes") and the middle is more of a climatology.

Daily mean minimum daily temperature and extremes

The plot shows the average and the extremes of the daily minimum temperature for each day of the year averaged over 30 years. The middle line is the average daily maximum temperature for that day which computed by taking the average over all available years for that day. The top line is the highest minimum temperature for that day over 30 years. The lower line is the lowest minimum temperature over all available years. The last two represent the range of minimum temperatures possible for that day (hence "extremes") and the middle is more of a climatology.

Daily mean precipitation and snowfall

Precipitation represents the total rainfall and snow. The amount of liquid from snow is sometimes measured by melting the snow and sometimes is calculated from assuming a ration of 1 inch snow= .1 inches of precipitation. The plot shows the daily average precipitation(blue) and snowfall(red) for each day over the 30 year time-period. Since there are relatively few days with measurable snowfall or precipitation over 30 (or less) the plots can be spiky and represent one storm. A 7 day smoother has been applied to the resulting values to decrease spikiness somewhat. As stated, precipitation amounts from snowfall are computed as 0.1 times the snowfall amount so they will tend to line up (though not always if the precipitation from snow was measured by actually melting the snow).