Help - Freeze Dates Reading the Table

The "Last Spring Freeze" column displays the earliest recorded, latest recorded, average, and median dates of the last freeze in the spring. "First Fall Freeze" refers to the earliest recorded, latest recorded, average, and median dates of the first freeze of the fall. "Freeze-Free" calculates the shortest, longest, average, and median period of time without a freeze for the given station.

The 'Period' and 'Years' of data recorded are also listed in the table. 'Period' refers to when the station went active to the present date or when the station went inactive. 'Years' refers to the number of years that enough data was recorded to calculate statistics according to the "10 Missing Day" standard, or if there are ten missing days before we reach a freeze date (Utah Climate-2nd edition 2007, pg 55 by Alan Moller and Rob Gillies). In these cases, we mark the season as invalid. If there is a 0 in the 'Years' column, the station had at least one good season (spring or fall) but no complete year.

Last Spring Freeze and First Fall Freeze

"Last Spring Freeze" shows the earliest recorded, latest recorded, average, and median dates of the last freeze in the spring. "First Fall Freeze" refers to the earliest recorded, latest recorded, average, and median dates of the first freeze of the fall. In the Northern Hemisphere, July 24 separates spring and fall for a given year, and in the Southern Hemisphere it is January 24. Starting at this date, for each year, we find the first occurrence of freezing minimum temperature in both spring and fall. If we do not find a freeze date the search continues into the previous and next years to find one. (i.e. a spring freeze date could be in the previous year\'s December based on the location\'s climate).

Freeze-Free Season

"Freeze-Free" calculates the shortest, longest, average, and median period of time without a freeze for the given station. If a freeze day is not found before the previous or following year, it is possible to have "Freeze-Free" season of up to two years. If there is not a valid spring and a fall freeze in the same year, we do not calculate the "Freeze-Free" season for a station. A 1 in the "Freeze-Free" columns indicates either the station has minimum temperatures that always fall below freezing or has one day in which the minimum temperature never reaches freezing. 729 days could indicate a never freeze year. 730 days indicates a leap year that had minimum temperatures that never fell below freezing.

Station Details

You may get detailed information about a page by clicking on the station name on the table.

Details include:

  • station name
    • station name
    • station id
    • latitude and longitude
    • elevation
    • country
    • state
    • period
    • years
    • Last Spring Freeze, First Fall Freeze and Freeze Free information including the years for minimum and maximum records

This information can be collected for all stations in a geographic area by exporting to csv on the Freeze Dates page.