Climate - The Dalles (Oregon)

The climate of The Dalles is moderately continental, with quite cold, rainy winters and hot, sunny summers.
The city is located in northern Oregon, 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.
During the winter, 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.
In summer, 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 average temperature of the coldest month (January) is of 2.2 °C (36 °F), that of the warmest month (July) is of 22.9 °C (73.3 °F). Here are the average temperatures.

Precipitation amounts to 355 millimeters (14 inches) per year: it is therefore quite scarce. It ranges from 5 mm (0.2 in) in the driest months (July, August) to 75 mm (3 in) in the wettest (December). Here is the average precipitation.

Best Time

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.

Back to the climate of Oregon.

The Dalles - Weather by month

Based on the period 1991-2020

---

In January, the coldest month of the year, the weather in The Dalles is usually cold. The average temperature is of 2.2 °C (36 °F), with a minimum of -1.6 °C (29.1 °F) and a maximum of 6.1 °C (43 °F).
On the coldest nights of the month, the temperature usually drops to around -8 °C (17 °F). However, it dropped to -19.5 °C (-3.1 °F) in January 1996.
On the warmest days of the month, the temperature usually reaches around 14.5 °C (57.5 °F). However, it reached 19.4 °C (66.9 °F) in January 2009.
Precipitation amounts to 60 mm (2.4 in), 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 7 kph (4 mph).

---

In February, the weather in The Dalles is usually quite cold. The average temperature is of 4.1 °C (39 °F), with a minimum of -1.2 °C (29.8 °F) and a maximum of 9.5 °C (49.1 °F).
On the coldest nights of the month, the temperature usually drops to around -7 °C (19 °F). However, it dropped to -20 °C (-4 °F) in February 1996.
On the warmest days of the month, the temperature usually reaches around 16 °C (61 °F). However, it reached 22 °C (71.6 °F) in February 1998.
Precipitation amounts to 40 mm (1.6 in), 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 8 kph (5 mph).

---

In March, the weather in The Dalles is usually quite mild. The average temperature is of 7.5 °C (46 °F), with a minimum of 1 °C (33.8 °F) and a maximum of 14 °C (57.2 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -4 °C (25 °F). However, it dropped to -13.3 °C (8.1 °F) in March 2019.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 21.5 °C (71 °F). However, it reached 26.6 °C (79.9 °F) in March 1994.
Precipitation amounts to 30 mm (1.2 in), distributed over 10 days.
The day lasts on average 12 hours and 0 minutes.
The average humidity is 65%.
The average wind speed is 11 kph (7 mph).

---

In April, the weather in The Dalles is usually mild. However, there are remarkable differences between night and day. The average temperature is of 11.1 °C (52 °F), with a minimum of 3.9 °C (39.1 °F) and a maximum of 18.2 °C (64.7 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -1 °C (30.5 °F). However, it dropped to -3.9 °C (25 °F) in April 2008.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 27.5 °C (81.5 °F). However, it reached 34.7 °C (94.5 °F) in April 1998.
Precipitation amounts to 25 mm (1 in), distributed over 8 days.
The day lasts on average 13 hours and 35 minutes.
The average humidity is 57%.
The average wind speed is 15 kph (9 mph).

---

In May, the weather in The Dalles is usually very mild. However, there are remarkable differences between night and day. The average temperature is of 15.6 °C (60 °F), with a minimum of 8.3 °C (46.9 °F) and a maximum of 23 °C (73.4 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 2.5 °C (36.5 °F). However, it dropped to -0.6 °C (30.9 °F) in May 2013.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 33 °C (92 °F). However, it reached 37.2 °C (99 °F) in May 2001.
Precipitation amounts to 20 mm (0.8 in), 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 17 kph (11 mph).

---

In June, the weather in The Dalles is usually warm. However, there are remarkable differences between night and day. The average temperature is of 19 °C (66 °F), with a minimum of 11.7 °C (53 °F) and a maximum of 26.3 °C (79.4 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 7.5 °C (45 °F). However, it dropped to 3.9 °C (39 °F) in June 2016.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 36.5 °C (98 °F). However, it reached 42.2 °C (108 °F) in June 1992.
Precipitation amounts to 10 mm (0.4 in), 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 20 kph (12 mph).

---

In July, the warmest month of the year, the weather in The Dalles is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 22.9 °C (73 °F), with a minimum of 14.6 °C (58.2 °F) and a maximum of 31.3 °C (88.3 °F).
On the coldest nights of the month, the temperature usually drops to around 10.5 °C (51 °F). However, it dropped to 8.3 °C (46.9 °F) in July 2012.
On the warmest days of the month, the temperature usually reaches around 40 °C (104 °F). However, it reached 44.2 °C (111.6 °F) in July 1998.
Precipitation amounts to only 5 mm (0.2 in), 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 21 kph (13 mph).

---

In August, the weather in The Dalles is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 22.8 °C (73 °F), with a minimum of 14.1 °C (57.4 °F) and a maximum of 31.4 °C (88.6 °F).
On the coldest nights of the month, the temperature usually drops to around 10 °C (50 °F). However, it dropped to 6.6 °C (43.9 °F) in August 1992.
On the warmest days of the month, the temperature usually reaches around 39.5 °C (103.5 °F). However, it reached 42.8 °C (109 °F) in August 2008.
Precipitation amounts to only 5 mm (0.2 in), distributed over 2 days.
The day lasts on average 14 hours and 0 minutes.
The average humidity is 44%.
The average wind speed is 18 kph (11 mph).

---

In September, the weather in The Dalles is usually warm. However, there are remarkable differences between night and day. The average temperature is of 18.4 °C (65 °F), with a minimum of 9.5 °C (49.1 °F) and a maximum of 27.2 °C (81 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 4.5 °C (40.5 °F). However, it dropped to -0.4 °C (31.3 °F) in September 2000.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 35.5 °C (96 °F). However, it reached 40 °C (104 °F) in September 2017.
Precipitation amounts to 10 mm (0.4 in), distributed over 2 days.
The day lasts on average 12 hours and 30 minutes.
The average humidity is 48%.
The average wind speed is 14 kph (8 mph).

---

In October, the weather in The Dalles is usually mild. However, there are remarkable differences between night and day. The average temperature is of 11.9 °C (53 °F), with a minimum of 4.2 °C (39.6 °F) and a maximum of 19.6 °C (67.2 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -2 °C (28.5 °F). However, it dropped to -9 °C (15.8 °F) in October 2002.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 27.5 °C (81.5 °F). However, it reached 33 °C (91.4 °F) in October 1997.
Precipitation amounts to 25 mm (1 in), distributed over 8 days.
The day lasts on average 10 hours and 55 minutes.
The average humidity is 62%.
The average wind speed is 10 kph (6 mph).

---

In November, the weather in The Dalles is usually quite cold. The average temperature is of 5.8 °C (42 °F), with a minimum of 0.7 °C (33.3 °F) and a maximum of 10.9 °C (51.6 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -6 °C (21.5 °F). However, it dropped to -16.2 °C (2.8 °F) in November 1993.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 19.5 °C (67.5 °F). However, it reached 25 °C (77 °F) in November 1994.
Precipitation amounts to 50 mm (2 in), 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 7 kph (5 mph).

---

In December, the weather in The Dalles is usually cold. The average temperature is of 2.3 °C (36 °F), with a minimum of -1.4 °C (29.4 °F) and a maximum of 6 °C (42.8 °F).
On the coldest nights of the month, the temperature usually drops to around -7.5 °C (18.5 °F). However, it dropped to -18.9 °C (-2 °F) in December 2013.
On the warmest days of the month, the temperature usually reaches around 13.5 °C (56.5 °F). However, it reached 18.9 °C (66 °F) in December 2015.
Precipitation amounts to 75 mm (3 in), 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 7 kph (5 mph).