Monthly outlook for Brennan, WA: average high 57.7°, average low 46.6°. That is 1.2° above the climate normal for October. Precipitation is expected on 4 days (about 1.3 inches), against a normal of 8 days and 3.8 inches. The warmest day looks like 16 October (68.4°), the coolest 18 October (39.9°).
57.7°/46.6°
Average high / low
+1.2°
Above normal
4 / 8
Wet days / normal
1.3 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
13 October – 22 October
58°
56.6°
+0.8°
23 October – 1 November
57°
53°
+2.2°
2 November – 11 November
at normal
50.5°
—
October records over 66 years
81.1°1 October 1987All-time high
21.6°31 October 1984All-time low
Climate normals and records are computed from the nearest reference point — Bellingham (6 mi).
Wed, 1461° / 48°0.02
61 °
Brennan, Wednesday, 14 October
Light rain. High 61°, low 48°.
Pressure30.33 inHg
Wind3.8 mph NE
Humidity82%
Visibility6.2 mi
Dew point51°
Thu, 1568° / 44°0
68 °
Brennan, Thursday, 15 October
Overcast. High 68°, low 44°.
Pressure30.33 inHg
Wind2.8 mph NE
Humidity67%
Visibility6.2 mi
Dew point51°
Fri, 1668° / 47°0
68 °
Brennan, Friday, 16 October
Partly cloudy. High 68°, low 47°.
Pressure30.12 inHg
Wind1.8 mph S
Humidity64%
Visibility6.2 mi
Dew point51°
Sat, 1761° / 48°0.11
61 °
Brennan, Saturday, 17 October
Light rain. High 61°, low 48°.
Pressure30.09 inHg
Wind10.2 mph S
Humidity76%
Visibility—
Dew point51°
Sun, 1856° / 40°0
56 °
Brennan, Sunday, 18 October
Partly cloudy. High 56°, low 40°.
Pressure30.00 inHg
Wind6.4 mph NE
Humidity73%
Visibility—
Dew point42°
Mon, 1951° / 48°0.61
51 °
Brennan, Monday, 19 October
Rain. High 51°, low 48°.
Pressure29.71 inHg
Wind8.4 mph SE
Humidity94%
Visibility—
Dew point48°
Tue, 2052° / 46°0.15
52 °
Brennan, Tuesday, 20 October
Light rain. High 52°, low 46°.
Pressure29.94 inHg
Wind7.1 mph S
Humidity89%
Visibility—
Dew point47°
Wed, 2153° / 44°0.02
53 °
Brennan, Wednesday, 21 October
Light rain. High 53°, low 44°.
Pressure30.09 inHg
Wind5.9 mph S
Humidity74%
Visibility—
Dew point42°
Thu, 2253° / 47°0.33
53 °
Brennan, Thursday, 22 October
Rain. High 53°, low 47°.
Pressure30.00 inHg
Wind12.3 mph S
Humidity86%
Visibility—
Dew point48°
Fri, 2353° / 48°0
53 °
Brennan, Friday, 23 October
Overcast. High 53°, low 48°.
Pressure30.47 inHg
Wind6.4 mph SE
Humidity88%
Visibility—
Dew point47°
Sat, 2451° / 47°0.03
51 °
Brennan, Saturday, 24 October
Light rain. High 51°, low 47°.
Pressure30.56 inHg
Wind3.9 mph E
Humidity88%
Visibility—
Dew point45°
Sun, 2557° / 46°0
57 °
Brennan, Sunday, 25 October
Overcast. High 57°, low 46°.
Pressure30.56 inHg
Wind5.9 mph NW
Humidity78%
Visibility—
Dew point45°
Mon, 2662° / 49°0
62 °
Brennan, Monday, 26 October
Overcast. High 62°, low 49°.
Pressure30.33 inHg
Wind3.9 mph NW
Humidity74%
Visibility—
Dew point47°
Tue, 2762° / 51°0
62 °
Brennan, Tuesday, 27 October
Mostly clear. High 62°, low 51°.
Pressure30.24 inHg
Wind3.4 mph NW
Humidity70%
Visibility—
Dew point48°
Wed, 2857° / 50°0
57 °
Brennan, Wednesday, 28 October
Mostly clear. High 57°, low 50°.
Pressure30.12 inHg
Wind1.7 mph E
Humidity75%
Visibility—
Dew point49°
From day 17 onward the outlook is built from 60-year climate statistics
Thu, 2952° / 42°0.2
52 °
Brennan, Thursday, 29 October
Climate normal for this date — 60-year average.
Average high52°
Average low42°
Average precipitation0.2 in
Chance of precipitation53%
Record high67° (1962)
Record low29° (1991)
Fri, 3052° / 42°0.27
52 °
Brennan, Friday, 30 October
Climate normal for this date — 60-year average.
Average high52°
Average low42°
Average precipitation0.27 in
Chance of precipitation57%
Record high61° (1987)
Record low31° (1972)
Sat, 3151° / 42°0.33
51 °
Brennan, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high51°
Average low42°
Average precipitation0.33 in
Chance of precipitation67%
Record high61° (1964)
Record low22° (1984)
Sun, 0152° / 41°0.25
52 °
Brennan, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high52°
Average low41°
Average precipitation0.25 in
Chance of precipitation50%
Record high65° (1969)
Record low31° (1984)
Mon, 0252° / 41°0.27
52 °
Brennan, Monday, 2 November
Climate normal for this date — 60-year average.
Average high52°
Average low41°
Average precipitation0.27 in
Chance of precipitation58%
Record high65° (1962)
Record low31° (1961)
Tue, 0351° / 42°0.33
51 °
Brennan, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high51°
Average low42°
Average precipitation0.33 in
Chance of precipitation63%
Record high64° (2010)
Record low29° (2017)
Wed, 0452° / 42°0.38
52 °
Brennan, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high52°
Average low42°
Average precipitation0.38 in
Chance of precipitation62%
Record high65° (1980)
Record low30° (2017)
Thu, 0551° / 41°0.22
51 °
Brennan, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high51°
Average low41°
Average precipitation0.22 in
Chance of precipitation65%
Record high64° (1980)
Record low28° (1971)
Fri, 0650° / 41°0.35
50 °
Brennan, Friday, 6 November
Climate normal for this date — 60-year average.
Average high50°
Average low41°
Average precipitation0.35 in
Chance of precipitation62%
Record high59° (2014)
Record low28° (2003)
Sat, 0750° / 42°0.34
50 °
Brennan, Saturday, 7 November
Climate normal for this date — 60-year average.
Average high50°
Average low42°
Average precipitation0.34 in
Chance of precipitation73%
Record high59° (1962)
Record low29° (2003)
Sun, 0850° / 41°0.25
50 °
Brennan, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high50°
Average low41°
Average precipitation0.25 in
Chance of precipitation60%
Record high67° (2016)
Record low28° (2022)
Mon, 0950° / 40°0.28
50 °
Brennan, Monday, 9 November
Climate normal for this date — 60-year average.
Average high50°
Average low40°
Average precipitation0.28 in
Chance of precipitation60%
Record high64° (2025)
Record low28° (2022)
Tue, 1050° / 40°0.24
50 °
Brennan, Tuesday, 10 November
Climate normal for this date — 60-year average.
Average high50°
Average low40°
Average precipitation0.24 in
Chance of precipitation53%
Record high64° (2025)
Record low28° (1966)
Wed, 1149° / 40°0.31
49 °
Brennan, Wednesday, 11 November
Climate normal for this date — 60-year average.
Average high49°
Average low40°
Average precipitation0.31 in
Chance of precipitation60%
Record high60° (1996)
Record low25° (1985)
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 Brennan, WA 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 Brennan, WA 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.