A late July heat wave helped clinch a record hot July for some Northwest cities. It's also helped set a record for the most 90-degree days in a year in Seattle and has given Portland its hottest temperatures since 2009.

A substantial warm up also occurred for places that saw snow early in July's last week in Montana, Idaho and Wyoming.

Northwest: Clinching a Record Hot July

A strong ridge of high pressure built over the Northwest as the jet stream bulged northward to the Canadian border. This allowed temperatures from 5 to 20 degrees above average to take hold across parts of Oregon, Washington, Idaho and Montana wrapping up July into the first weekend of August.

(MORE: Strange July Weather Pattern Brings Snow, Tornadoes )

The heat wave helped clinch the hottest July on record for the following cities (all data is preliminary):

Seattle: July 2015 average monthly temperature is 71.2 degrees. This beats the old July record of 69.5 degrees set in 2009. This also beats out August 1967 (71.1 degrees) for the hottest of any month on record. Records date back to 1894.

July 2015 average monthly temperature is 71.2 degrees. This beats the old July record of 69.5 degrees set in 2009. This also beats out August 1967 (71.1 degrees) for the hottest of any month on record. Records date back to 1894. Salem, Oregon: July 2015 average monthly temperature is 73.1 degrees. This beats the old record of 72.5 degrees for hottest of any month set in both July and August 2014. Records date back to 1893.

July 2015 average monthly temperature is 73.1 degrees. This beats the old record of 72.5 degrees for hottest of any month set in both July and August 2014. Records date back to 1893. Eugene, Oregon: July 2015 average monthly temperature is 71.5 degrees. This beats the old July record of 71 degrees set in 1958. Records date back to 1912.

Portland, Oregon , saw consecutive days with 100-degree heat, topping out at 103 degrees on Thursday and 101 degrees on Friday. Thursday's 103 was the hottest temperature there since July 29, 2009. Those hot temperatures have vaulted Portland to its second hottest July on record with an average temperature of 73.9 degrees, falling just behind 1985 which had an average of 74.1 degrees.

Seattle saw its twelfth 90-degree day of 2015 on Saturday, which is a new record for the most 90-degree days in a calendar year. The old record was nine days set in 1958. The Emerald City averages just two days with 90-degree heat annually.

Eugene and Salem , Oregon, both set daily record highs on Thursday by topping out at 105 degrees. This was one degree shy of an all-time July record high in Eugene. Another daily record high of 103 degrees was set in Eugene on Friday. Eugene has also set a record for the most days in a year with temperatures at or above 100 degrees with seven days through Saturday, the previous record was five set in 1978. Eugene also tied a record long 100-degree-plus streak of four straight days with August 1981. Daily record highs were recorded in both Eugene (100 degrees) and Salem (100 degrees) on Saturday.

Farther south, Roseburg, Oregon , was one degree short of an all-time record high on Thursday when it topped out at 108 degrees. Friday's high was 107 degrees which set a new daily record.

In Northern California, Redding topped out at 114 degrees on Thursday, which set a new record for the date. Sacramento (downtown) set a daily record high of 107 degrees on Wednesday.

Boise, Idaho , squeaked just past 100 degrees on Sunday after recording a high in the low 100s Saturday. Idaho's capital fell well short of its June 28 high of 110 degrees, which set an all-time record for June.

For parts of Montana, this is quite a change from the way the week started. For example, Missoula, Montana , saw rain with temperatures in the upper 40s and 50s on Monday afternoon. Highs were in the low to middle 90s there on Thursday and Friday and temperatures reached 98 degrees on Saturday.

High elevation areas that saw snow on Monday in the northern Rockies will also see significant temperature rises. Big Sky, Montana , reached the lower 80s on Sunday and Grand Targhee, Wyoming which saw 1.5 inches of snow early this week saw a high in the mid 80s Sunday.

MORE ON WEATHER.COM: Northern Rockies See July Snow