, on the banks of the Columbia River, in the plains, but east of the Cascade Range, therefore in an arid area. To the southwest, 45 km (28 mi), and clearly visible from the city, is Mount Hood, the highest peak in Oregon, while to the north, in the state of Washington, we find Mount Adams and Mount St. Helens.
, there are fairly mild periods, but also cold periods, in which the minimum temperature can drop to -10 °C (14 °F). Once every few years, cold waves can occur, during which the temperature can drop to -20 °C (-4 °F). Snowfalls are rare. On average, 12 cm (4.7 in) of snow fall per year.
, there are several very hot days, alternating with cooler periods. On the hottest days of the year, the temperature generally reaches 39/40 °C (102/104 °F), but sometimes even higher.
At the end of June 2021, in The Dalles and Hermiston, during an exceptional heat wave, the temperature reached 47.8 °C (118 °F), a value that represents the record of the entire state of Oregon.
The best times to visit The Dalles are spring and autumn, and in particular the months of May and September, to avoid both the winter cold and the summer heat.
. Here are the average temperatures.
January, the coldest month of the year, is generally a cold month. The average temperature is of
2.2 °C, with a minimum of
-1.6 °C and a maximum of
6.1 °C.

On the coldest nights of the month, the temperature usually drops to around
-8 °C. However, it dropped to
-19.5 °C in January 1996.

On the warmest days of the month, the temperature usually reaches around
14.5 °C. However, it reached
19.4 °C in January 2009.

Precipitation amounts to
60 mm, distributed over 12 days.
The day lasts on average 9 hours and 10 minutes.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is of
7.1 kph.
February is generally a quite cold month. The average temperature is of
4.1 °C, with a minimum of
-1.2 °C and a maximum of
9.5 °C.

On the coldest nights of the month, the temperature usually drops to around
-7 °C. However, it dropped to
-20 °C in February 1996.

On the warmest days of the month, the temperature usually reaches around
16 °C. However, it reached
22 °C in February 1998.

Precipitation amounts to
40 mm, distributed over 10 days.
The day lasts on average 10 hours and 25 minutes.
The average humidity is 75%. Hence, the air is normally humid.
The average wind speed is of
8.3 kph.
March is generally a quite mild month. The average temperature is of
7.5 °C, with a minimum of
1 °C and a maximum of
14 °C.

On the coldest nights of the month, the temperature usually drops to around
-4 °C. However, it dropped to
-13.3 °C in March 2019.

On the warmest days of the month, the temperature usually reaches around
21.5 °C. However, it reached
26.6 °C in March 1994.

Precipitation amounts to
30 mm, distributed over 10 days.
The day lasts on average 12 hours and 0 minutes.
The average humidity is 65%.
The average wind speed is of
11.3 kph.
April is generally a mild month. However, there are remarkable differences between night and day. The average temperature is of
11.1 °C, with a minimum of
3.9 °C and a maximum of
18.2 °C.

On the coldest nights of the month, the temperature usually drops to around
-1 °C. However, it dropped to
-3.9 °C in April 2008.

On the warmest days of the month, the temperature usually reaches around
27.5 °C. However, it reached
34.7 °C in April 1998.

Precipitation amounts to
25 mm, distributed over 8 days.
The day lasts on average 13 hours and 35 minutes.
The average humidity is 57%.
The average wind speed is of
15.2 kph.
May is generally a very mild month. However, there are remarkable differences between night and day. The average temperature is of
15.6 °C, with a minimum of
8.3 °C and a maximum of
23 °C.

On the coldest nights of the month, the temperature usually drops to around
2.5 °C. However, it dropped to
-0.6 °C in May 2013.

On the warmest days of the month, the temperature usually reaches around
33 °C. However, it reached
37.2 °C in May 2001.

Precipitation amounts to
20 mm, distributed over 6 days.
The day lasts on average 15 hours and 0 minutes. So the days are long.
The average humidity is 51%.
The average wind speed is of
17.3 kph.
June is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of
19 °C, with a minimum of
11.7 °C and a maximum of
26.3 °C.

On the coldest nights of the month, the temperature usually drops to around
7.5 °C. However, it dropped to
3.9 °C in June 2016.

On the warmest days of the month, the temperature usually reaches around
36.5 °C. However, it reached
42.2 °C in June 1992.

Precipitation amounts to
10 mm, distributed over 3 days.
The day lasts on average 15 hours and 35 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
The average humidity is 48%.
The average wind speed is of
20 kph.
July, the warmest month of the year, is generally a warm to hot month. However, there are remarkable differences between night and day. The average temperature is of
22.9 °C, with a minimum of
14.6 °C and a maximum of
31.3 °C.

On the coldest nights of the month, the temperature usually drops to around
10.5 °C. However, it dropped to
8.3 °C in July 2012.

On the warmest days of the month, the temperature usually reaches around
40 °C. However, it reached
44.2 °C in July 1998.

Precipitation amounts to only
5 mm, and all occurs in one day.
The day lasts on average 15 hours and 10 minutes. So the days are long.
The average humidity is 43%.
The average wind speed is of
20.6 kph.
August is generally a warm to hot month. However, there are remarkable differences between night and day. The average temperature is of
22.8 °C, with a minimum of
14.1 °C and a maximum of
31.4 °C.

On the coldest nights of the month, the temperature usually drops to around
10 °C. However, it dropped to
6.6 °C in August 1992.

On the warmest days of the month, the temperature usually reaches around
39.5 °C. However, it reached
42.8 °C in August 2008.

Precipitation amounts to only
5 mm, distributed over 2 days.
The day lasts on average 14 hours and 0 minutes.
The average humidity is 44%.
The average wind speed is of
18.1 kph.
September is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of
18.4 °C, with a minimum of
9.5 °C and a maximum of
27.2 °C.

On the coldest nights of the month, the temperature usually drops to around
4.5 °C. However, it dropped to
-0.4 °C in September 2000.

On the warmest days of the month, the temperature usually reaches around
35.5 °C. However, it reached
40 °C in September 2017.

Precipitation amounts to
10 mm, distributed over 2 days.
The day lasts on average 12 hours and 30 minutes.
The average humidity is 48%.
The average wind speed is of
13.5 kph.
October is generally a mild month. However, there are remarkable differences between night and day. The average temperature is of
11.9 °C, with a minimum of
4.2 °C and a maximum of
19.6 °C.

On the coldest nights of the month, the temperature usually drops to around
-2 °C. However, it dropped to
-9 °C in October 2002.

On the warmest days of the month, the temperature usually reaches around
27.5 °C. However, it reached
33 °C in October 1997.

Precipitation amounts to
25 mm, distributed over 8 days.
The day lasts on average 10 hours and 55 minutes.
The average humidity is 62%.
The average wind speed is of
9.7 kph.
November is generally a quite cold month. The average temperature is of
5.8 °C, with a minimum of
0.7 °C and a maximum of
10.9 °C.

On the coldest nights of the month, the temperature usually drops to around
-6 °C. However, it dropped to
-16.2 °C in November 1993.

On the warmest days of the month, the temperature usually reaches around
19.5 °C. However, it reached
25 °C in November 1994.

Precipitation amounts to
50 mm, distributed over 12 days.
The day lasts on average 9 hours and 30 minutes.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is of
7.3 kph.
December is generally a cold month. The average temperature is of
2.3 °C, with a minimum of
-1.4 °C and a maximum of
6 °C.

On the coldest nights of the month, the temperature usually drops to around
-7.5 °C. However, it dropped to
-18.9 °C in December 2013.

On the warmest days of the month, the temperature usually reaches around
13.5 °C. However, it reached
18.9 °C in December 2015.

Precipitation amounts to
75 mm, distributed over 11 days.
The day lasts on average 8 hours and 50 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is of
7.4 kph.