Indian Head Cda Weather Records (CA004013480)

The annual mean temperature here has risen by 0.2 C (0.1 to 0.3) per decade over 1891 to 1983. In Fahrenheit: 0.3 F (0.2 to 0.5) per decade. The slope is a straight line fitted to 92 complete years; the brackets give its 95 percent interval.

Across 92 years with a frost, the median last spring frost at Indian Head Cda falls on 29 May and the median first autumn frost on 11 September, which leaves a median of 102 days between them.

In 1954 to 1983 the median growing season was 109 days. That is 8 days more than in 1891 to 1921.

Fitted over all years, the growing season changes by +1.5 days per decade at this station.

A day with at least 38.3 mm (1.5 in) of rain is expected about once in 2 years. A day with at least 99.9 mm (3.9 in) of rain is expected about once in 100 years.

The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 84 years of values from 1891 to 1983.

A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.

The largest wettest-day totals in the fit: 108.2 mm (4.3 in) in 1920; 102.0 mm (4.0 in) in 1982; 89.2 mm (3.5 in) in 1981.

3 changes were suspected in the annual mean temperature of Indian Head Cda, at 1924, 1959 and 1978. Each is measured against neighbouring stations.

• Relative to 5 neighbouring stations, the station's annual mean temperature from 1924 ran 0.3 C (0.5 F) higher than in the years before (possible change).
• Relative to 5 neighbouring stations, the station's annual mean temperature from 1959 ran 0.2 C (0.4 F) higher than in the years before (likely change).
• Relative to 5 neighbouring stations, the station's annual mean temperature from 1978 ran 0.2 C (0.3 F) lower than in the years before (possible change).