As of 11:25 PDT

Weather in South Lake Oswego, OR

72°

South Lake Oswego, Sunday, 9 August, 11:25

Partly cloudy. Feels like 71°. High 84°, low 56°.

Pressure30.06 inHg

Wind3 mph E

Humidity59%

Visibility6.2 mi

Dew point56°

See detailed hourly forecast

Monthly outlook for South Lake Oswego, OR: average high 90.9°, average low 61°. That is 5.2° above the climate normal for August. Precipitation is expected on 0 days (about 0.0 inches), against a normal of 2 days and 0.5 inches. The warmest day looks like 24 August (102.4°), the coolest 10 August (53.5°).

90.9°/61°

Average high / low

+5.2°

Above normal

0 / 2

Wet days / normal

0.0 in

Precipitation this month

Ten-day blocks vs climate normal

Period	Forecast high	Normal	Difference
9 August – 18 August	88.1°	82.6°	+3°
19 August – 28 August	95.6°	79.9°	+8.7°
29 August – 7 September	at normal	78.3°	—

August records over 66 years

105.3°14 August 2023All-time high

44.2°28 August 1960All-time low

Climate normals and records are computed from the nearest reference point — Johnson City (5 mi).

Mon, 1083° / 53°

83 °

South Lake Oswego, Monday, 10 August

Clear. High 83°, low 53°.

Pressure30.06 inHg

Wind4.8 mph N

Humidity37%

Visibility6.2 mi

Dew point48°

Tue, 1186° / 56°

86 °

South Lake Oswego, Tuesday, 11 August

Clear. High 86°, low 56°.

Pressure30.09 inHg

Wind4.2 mph N

Humidity37%

Visibility6.2 mi

Dew point49°

Wed, 1285° / 60°

85 °

South Lake Oswego, Wednesday, 12 August

Clear. High 85°, low 60°.

Pressure30.00 inHg

Wind4.9 mph N

Humidity42%

Visibility6.2 mi

Dew point51°

Thu, 1389° / 58°

89 °

South Lake Oswego, Thursday, 13 August

Clear. High 89°, low 58°.

Pressure29.83 inHg

Wind8.1 mph NW

Humidity32%

Visibility—

Dew point48°

Fri, 1491° / 62°

91 °

South Lake Oswego, Friday, 14 August

Overcast. High 91°, low 62°.

Pressure29.85 inHg

Wind5.9 mph NW

Humidity29%

Visibility—

Dew point48°

Sat, 1590° / 62°

90 °

South Lake Oswego, Saturday, 15 August

Overcast. High 90°, low 62°.

Pressure29.97 inHg

Wind6.6 mph N

Humidity32%

Visibility—

Dew point50°

Sun, 1692° / 62°

92 °

South Lake Oswego, Sunday, 16 August

Partly cloudy. High 92°, low 62°.

Pressure30.03 inHg

Wind7.5 mph NW

Humidity23%

Visibility—

Dew point44°

Mon, 1789° / 62°

89 °

South Lake Oswego, Monday, 17 August

Clear. High 89°, low 62°.

Pressure30.09 inHg

Wind10 mph N

Humidity23%

Visibility—

Dew point42°

Tue, 1892° / 60°

92 °

South Lake Oswego, Tuesday, 18 August

Mostly clear. High 92°, low 60°.

Pressure30.06 inHg

Wind5.3 mph N

Humidity18%

Visibility—

Dew point37°

Wed, 1995° / 64°

95 °

South Lake Oswego, Wednesday, 19 August

Clear. High 95°, low 64°.

Pressure30.00 inHg

Wind7.5 mph N

Humidity23%

Visibility—

Dew point46°

Thu, 2092° / 64°

92 °

South Lake Oswego, Thursday, 20 August

Clear. High 92°, low 64°.

Pressure30.00 inHg

Wind9.6 mph NW

Humidity27%

Visibility—

Dew point49°

Fri, 2192° / 62°

92 °

South Lake Oswego, Friday, 21 August

Clear. High 92°, low 62°.

Pressure29.94 inHg

Wind8.7 mph N

Humidity26%

Visibility—

Dew point46°

Sat, 2295° / 63°

95 °

South Lake Oswego, Saturday, 22 August

Clear. High 95°, low 63°.

Pressure29.97 inHg

Wind8.6 mph N

Humidity27%

Visibility—

Dew point49°

Sun, 2398° / 65°

98 °

South Lake Oswego, Sunday, 23 August

Clear. High 98°, low 65°.

Pressure30.00 inHg

Wind10 mph N

Humidity25%

Visibility—

Dew point49°

Mon, 24102° / 68°

102 °

South Lake Oswego, Monday, 24 August

Partly cloudy. High 102°, low 68°.

Pressure29.83 inHg

Wind4.2 mph N

Humidity19%

Visibility—

Dew point45°

From day 17 onward the outlook is built from 60-year climate statistics

Tue, 2580° / 56°

0.06

80 °

South Lake Oswego, Tuesday, 25 August

Climate normal for this date — 60-year average.

Average high80°

Average low56°

Average precipitation0.06 in

Chance of precipitation13%

Record high95° (1967)

Record low48° (1993)

Wed, 2681° / 56°

0.02

81 °

South Lake Oswego, Wednesday, 26 August

Climate normal for this date — 60-year average.

Average high81°

Average low56°

Average precipitation0.02 in

Chance of precipitation8%

Record high99° (1986)

Record low47° (1993)

Thu, 2780° / 57°

0.04

80 °

South Lake Oswego, Thursday, 27 August

Climate normal for this date — 60-year average.

Average high80°

Average low57°

Average precipitation0.04 in

Chance of precipitation15%

Record high97° (1972)

Record low49° (1962)

Fri, 2881° / 56°

0.03

81 °

South Lake Oswego, Friday, 28 August

Climate normal for this date — 60-year average.

Average high81°

Average low56°

Average precipitation0.03 in

Chance of precipitation8%

Record high100° (1967)

Record low44° (1960)

Sat, 2980° / 57°

0.06

80 °

South Lake Oswego, Saturday, 29 August

Climate normal for this date — 60-year average.

Average high80°

Average low57°

Average precipitation0.06 in

Chance of precipitation20%

Record high95° (2007)

Record low46° (1965)

Sun, 3077° / 56°

0.06

77 °

South Lake Oswego, Sunday, 30 August

Climate normal for this date — 60-year average.

Average high77°

Average low56°

Average precipitation0.06 in

Chance of precipitation28%

Record high97° (1987)

Record low46° (1966)

Mon, 3178° / 56°

0.05

78 °

South Lake Oswego, Monday, 31 August

Climate normal for this date — 60-year average.

Average high78°

Average low56°

Average precipitation0.05 in

Chance of precipitation18%

Record high99° (1987)

Record low47° (2006)

Tue, 0178° / 56°

0.06

78 °

South Lake Oswego, Tuesday, 1 September

Climate normal for this date — 60-year average.

Average high78°

Average low56°

Average precipitation0.06 in

Chance of precipitation20%

Record high98° (1988)

Record low43° (1973)

Wed, 0279° / 55°

0.06

79 °

South Lake Oswego, Wednesday, 2 September

Climate normal for this date — 60-year average.

Average high79°

Average low55°

Average precipitation0.06 in

Chance of precipitation17%

Record high105° (1988)

Record low46° (1960)

Thu, 0378° / 56°

0.05

78 °

South Lake Oswego, Thursday, 3 September

Climate normal for this date — 60-year average.

Average high78°

Average low56°

Average precipitation0.05 in

Chance of precipitation18%

Record high95° (2017)

Record low45° (1964)

Fri, 0479° / 55°

0.03

79 °

South Lake Oswego, Friday, 4 September

Climate normal for this date — 60-year average.

Average high79°

Average low55°

Average precipitation0.03 in

Chance of precipitation15%

Record high100° (2017)

Record low45° (2000)

Sat, 0578° / 55°

0.05

78 °

South Lake Oswego, Saturday, 5 September

Climate normal for this date — 60-year average.

Average high78°

Average low55°

Average precipitation0.05 in

Chance of precipitation13%

Record high98° (2024)

Record low45° (1969)

Sun, 0678° / 55°

0.08

78 °

South Lake Oswego, Sunday, 6 September

Climate normal for this date — 60-year average.

Average high78°

Average low55°

Average precipitation0.08 in

Chance of precipitation18%

Record high95° (2014)

Record low46° (1960)

Mon, 0778° / 55°

0.04

78 °

South Lake Oswego, Monday, 7 September

Climate normal for this date — 60-year average.

Average high78°

Average low55°

Average precipitation0.04 in

Chance of precipitation17%

Record high95° (2011)

Record low44° (1971)

About the monthly outlook

How accurate is a 30-day forecast?

The first 16 days come from weather models — reliable for the first 3–5 days and progressively less so after that. Days 17 through 30 for South Lake Oswego, OR are built from the climate normal, the 60-year average, so they show typical weather for those dates rather than a specific forecast.

What does "above normal" mean?

We compare the forecast against the climate normal for those exact calendar days, computed from 60 years of observations. The deviation shows how much the coming month differs from a typical one.

Where do the 66-year records come from?

They are real temperature extremes recorded in South Lake Oswego, OR since 1960: the highest and lowest reading for each calendar date, with the year it happened.

How often is it updated?

The forecast portion refreshes every hour; the climate portion is based on long-term data and stays stable.