What is “normal” weather?
The World Meteorological Organization established a standard for what is normal. It uses a 30-year span from which to calculate normals. Precipitation and extreme temperatures are most commonly derived when expressing normals. Every decade, the 30-year span is updated. Up until December 31, 2000 normals were calculated from January 1, 1961 to January 1, 1991. Now in 2001 the normals are derived from January 1, 1971 to January 1, 2001. To see the pattern used to determine normals, see below: 1960s = Jan 01, 1931 – Jan 01, 1961 1970s = Jan 01, 1941 – Jan 01, 1971 1980s = Jan 01, 1951 – Jan 01, 1981 1990s = Jan 01, 1961 – Jan 01, 1991 2000s = Jan 01, 1971 – Jan 01, 2001 We currently use the Jan-1971 to Jan-2001 span to calculate normals. Be aware that comparing a long-term average with daily absolute totals can be like comparing apples and oranges. The two will almost invariably be different. It is misleading to hear your local weather wo/man tell you that we are “above” or “below what is
