Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
I live near Nashville, TN, so I'm going to use it as it's the nearest NWS weather station. We are a Cfa climate, but in some cold years, we are a Dfa. Our coldest month averages 37.7 F / 3.2 C, and our warmest is 79.4 F / 26.3 C. Summer months lack the variability to make us a Dfb or Cfb in some years.
1985 was a Dfa year, with a coldest month average of 28 F / -2 C. If you really want to get nitpicky and use the -3 C isotherm, then 1977, with 25 F / -4 C qualifies.
Pittsburgh averages 28.4F/−2.0C in January and 72.6F/22.6C in July, so in many years the coldest month will average −3.0C or less, and, with less frequency, during particularly cool summers such as 2004 or 2000 no month will average above 22.0C. Even more rarely, the cold will be weak enough for the year to be Cfa. Using the 0C coldest month isotherm, Cfb years are non-existent (1990 was close); however, if using −3.0C, Cfb years are commonplace. So, all four of Dfa, Dfb, Cfa, Cfb are fair game in any year. This could make a case for PIT being a transitional climate.
Quote:
Originally Posted by wawa1992
I live near Nashville, TN, so I'm going to use it as it's the nearest NWS weather station. We are a Cfa climate, but in some cold years, we are a Dfa. Our coldest month averages 37.7 F / 3.2 C, and our warmest is 79.4 F / 26.3 C. Summer months lack the variability to make us a Dfb or Cfb in some years.
1985 was a Dfa year, with a coldest month average of 28 F / -2 C. If you really want to get nitpicky and use the -3 C isotherm, then 1977, with 25 F / -4 C qualifies.
The same situation with Washington, DC. January averages 36.0F/2.2C, July 79.8F/26.6C. The coolest July was 1891 at 72.0F, so the third letter has always been "a". DC occasionally is colder than 0C in its coldest month (5 times since 2000), but reaching a −3.0C average is exceedingly rare, with only 8 such months, all in different years/cold seasons, since 1871. Only 8 years have been truly Dfa. Defining winter and summer in a meteorological sense, some years are Cwa, most recently 2009 (0.35" in Feb vs 5.86" in Jun).
Interestingly enough, DC, at 30.8F averaged 2 to 3F warmer than Nashville in January 1985.
14 years - 1990,1994,1997,1999,2001,2002,2003,2004,2007,2008, 2010,2011,2012,2013 were mediterranean (Csa).
9 years - 1991,1992,1993,1995,1996,2000,2005,2006,2009 were humid subtropical (Cfa), which is the Koppen classification for the area.
1 year - 1998 was semi-arid, if we take a threshold of 400 mm of rainfall.
This weather station (Prospect) takes account for most of western Sydney, which is under Koppen's Cfa (humid subtropical).
We were semi-arid in 1888 (494mm), 1902 (469mm), 1907 (489mm) 1944 (394mm), 1957 (498mm). To note, I usually don't consider yearly rainfall above 500mm to semi-arid, not unless if the places have a yearly average temp of 28-30C - in which the high evaporation rate helps.
We were oceanic in 1967 and 1971 because of the lower summer/winter temps and above average rainfall (15C high in winter, 26C in summer, 900mm-1000mm rainfall).
It often happens. Last time was 2013, when we were Cfa. Last time we were Dfb using the -3°C threshold was in 1956. Using the 0°C threshold, it happens once or twice a decade, three years in a row between 1985 and 1987.
Over the last 20 years, 1994, 1995, 1997, 2003, 2006 and 2013 were Cfa.
1921 was BSh.
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
