Κόσμος

Β. Αμερική

Portland





Number of days available for climatic review

ΠαράμετροςΙανΦεβ ΜαρΑπρΙουνΙουλ
Tmax209318952091202920762023
Tmin210119002093202820842030
Διάρκεια Ηλιοφάνειας62576260124150
Υετός186169187181186180
Υγρασία/Ορατότητα 183166183177181176


ΠαράμετροςΑυγΣεπΟκτΝοεΔεκ(null)
Tmax208620932058212020462114
Tmin209720922063212220552118
Διάρκεια Ηλιοφάνειας1559390626062
Υετός188190210215210217
Υγρασία/Ορατότητα 182183205205199211


Climate data is usually derived from meteorological data of a certain number of years. The actual number of recorded years may vary from only a couple to 50 years or more. The quality of climate data depends on the number of available recorded years. Fewer years means less reliable data. The standart-period for reliable climate data is 30 years. For example, the mean monthly temperature for, let's say January, would ideally calculated from a total number of 930 recorded January-days. However, the usual number of recorded days is much smaller. The table above shows the actual number of recorded days for every parameter measured.