Monthly outlook for Portland, NY: average high 77.6°, average low 64.5°. That is 2° above the climate normal for August. Precipitation is expected on 7 days (about 0.7 inches), against a normal of 8 days and 2.5 inches. The warmest day looks like 20 August (86.8°), the coolest 15 August (55.6°).
77.6°/64.5°
Average high / low
+2°
Above normal
7 / 8
Wet days / normal
0.7 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
9 August – 18 August
75.1°
74.6°
+0.2°
19 August – 28 August
81.8°
73.6°
+4.5°
29 August – 7 September
at normal
72.3°
—
August records over 66 years
90.9°3 August 1988All-time high
44.6°30 August 1965All-time low
Climate normals and records are computed from the nearest reference point — Sinclairville (13 mi).
Mon, 1083° / 67°0.18
83 °
Portland, Monday, 10 August
Light rain. High 83°, low 67°.
Pressure29.91 inHg
Wind17 mph SW
Humidity77%
Visibility6.2 mi
Dew point67°
Tue, 1177° / 69°0.07
77 °
Portland, Tuesday, 11 August
Light rain. High 77°, low 69°.
Pressure29.94 inHg
Wind9.2 mph W
Humidity53%
Visibility6.2 mi
Dew point56°
Wed, 1277° / 69°0.05
77 °
Portland, Wednesday, 12 August
Light rain. High 77°, low 69°.
Pressure29.77 inHg
Wind9 mph W
Humidity91%
Visibility6.2 mi
Dew point68°
Thu, 1371° / 62°0.06
71 °
Portland, Thursday, 13 August
Light rain. High 71°, low 62°.
Pressure29.91 inHg
Wind17.9 mph N
Humidity49%
Visibility—
Dew point49°
Fri, 1468° / 58°0.01
68 °
Portland, Friday, 14 August
Light rain. High 68°, low 58°.
Pressure30.09 inHg
Wind14.6 mph N
Humidity58%
Visibility—
Dew point52°
Sat, 1570° / 56°0
70 °
Portland, Saturday, 15 August
Overcast. High 70°, low 56°.
Pressure30.27 inHg
Wind11.3 mph NW
Humidity51%
Visibility—
Dew point49°
Sun, 1671° / 58°0
71 °
Portland, Sunday, 16 August
Overcast. High 71°, low 58°.
Pressure30.15 inHg
Wind7 mph S
Humidity61%
Visibility—
Dew point53°
Mon, 1773° / 60°0.01
73 °
Portland, Monday, 17 August
Light rain. High 73°, low 60°.
Pressure30.03 inHg
Wind9.6 mph W
Humidity56%
Visibility—
Dew point55°
Tue, 1874° / 63°0
74 °
Portland, Tuesday, 18 August
Clear. High 74°, low 63°.
Pressure30.06 inHg
Wind8.2 mph N
Humidity60%
Visibility—
Dew point58°
Wed, 1980° / 62°0
80 °
Portland, Wednesday, 19 August
Partly cloudy. High 80°, low 62°.
Pressure30.06 inHg
Wind6.6 mph SE
Humidity49%
Visibility—
Dew point56°
Thu, 2087° / 67°0
87 °
Portland, Thursday, 20 August
Overcast. High 87°, low 67°.
Pressure29.91 inHg
Wind10.6 mph S
Humidity50%
Visibility—
Dew point63°
Fri, 2184° / 71°0.09
84 °
Portland, Friday, 21 August
Light rain. High 84°, low 71°.
Pressure29.83 inHg
Wind10.4 mph W
Humidity76%
Visibility—
Dew point74°
Sat, 2280° / 66°0
80 °
Portland, Saturday, 22 August
Mostly clear. High 80°, low 66°.
Pressure30.00 inHg
Wind8.7 mph NE
Humidity51%
Visibility—
Dew point58°
Sun, 2385° / 70°0.07
85 °
Portland, Sunday, 23 August
Light rain. High 85°, low 70°.
Pressure29.91 inHg
Wind12.9 mph NE
Humidity66%
Visibility—
Dew point67°
Mon, 2474° / 68°0.19
74 °
Portland, Monday, 24 August
Rain. High 74°, low 68°.
Pressure30.09 inHg
Wind16 mph NE
Humidity90%
Visibility—
Dew point66°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2574° / 60°0.13
74 °
Portland, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high74°
Average low60°
Average precipitation0.13 in
Chance of precipitation37%
Record high85° (2021)
Record low50° (2019)
Wed, 2675° / 60°0.12
75 °
Portland, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high75°
Average low60°
Average precipitation0.12 in
Chance of precipitation42%
Record high83° (1993)
Record low49° (2017)
Thu, 2775° / 61°0.2
75 °
Portland, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high75°
Average low61°
Average precipitation0.2 in
Chance of precipitation52%
Record high85° (2024)
Record low49° (2017)
Fri, 2874° / 62°0.19
74 °
Portland, Friday, 28 August
Climate normal for this date — 60-year average.
Average high74°
Average low62°
Average precipitation0.19 in
Chance of precipitation50%
Record high85° (2018)
Record low48° (1986)
Sat, 2973° / 61°0.17
73 °
Portland, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high73°
Average low61°
Average precipitation0.17 in
Chance of precipitation42%
Record high85° (2022)
Record low46° (1982)
Sun, 3073° / 60°0.13
73 °
Portland, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high73°
Average low60°
Average precipitation0.13 in
Chance of precipitation42%
Record high86° (1991)
Record low45° (1965)
Mon, 3173° / 59°0.14
73 °
Portland, Monday, 31 August
Climate normal for this date — 60-year average.
Average high73°
Average low59°
Average precipitation0.14 in
Chance of precipitation37%
Record high85° (1962)
Record low45° (2025)
Tue, 0173° / 59°0.09
73 °
Portland, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high73°
Average low59°
Average precipitation0.09 in
Chance of precipitation25%
Record high84° (2010)
Record low46° (2017)
Wed, 0273° / 59°0.19
73 °
Portland, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high73°
Average low59°
Average precipitation0.19 in
Chance of precipitation48%
Record high86° (2011)
Record low46° (2017)
Thu, 0372° / 59°0.13
72 °
Portland, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high72°
Average low59°
Average precipitation0.13 in
Chance of precipitation40%
Record high86° (2011)
Record low46° (2024)
Fri, 0472° / 59°0.14
72 °
Portland, Friday, 4 September
Climate normal for this date — 60-year average.
Average high72°
Average low59°
Average precipitation0.14 in
Chance of precipitation37%
Record high85° (1973)
Record low48° (1987)
Sat, 0572° / 59°0.12
72 °
Portland, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high72°
Average low59°
Average precipitation0.12 in
Chance of precipitation42%
Record high85° (2018)
Record low48° (1994)
Sun, 0672° / 58°0.1
72 °
Portland, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high72°
Average low58°
Average precipitation0.1 in
Chance of precipitation40%
Record high87° (2007)
Record low46° (2000)
Mon, 0771° / 58°0.15
71 °
Portland, Monday, 7 September
Climate normal for this date — 60-year average.
Average high71°
Average low58°
Average precipitation0.15 in
Chance of precipitation40%
Record high85° (2007)
Record low45° (1962)
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 Portland, NY 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 Portland, NY 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.