Monthly outlook for Islandia, NY: average high 83.1°, average low 70.8°. That is 2.3° above the climate normal for August. Precipitation is expected on 5 days (about 0.6 inches), against a normal of 5 days and 2.2 inches. The warmest day looks like 9 August (89.9°), the coolest 15 August (63.8°).
83.1°/70.8°
Average high / low
+2.3°
Above normal
5 / 5
Wet days / normal
0.6 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
9 August – 18 August
82.4°
79.7°
+1.5°
19 August – 28 August
84.2°
78.1°
+3.4°
29 August – 7 September
at normal
76.7°
—
August records over 66 years
95.2°2 August 1975All-time high
51.8°29 August 1982All-time low
Climate normals and records are computed from the nearest reference point — Smithtown (5 mi).
Mon, 1086° / 71°0
86 °
Islandia, Monday, 10 August
Partly cloudy. High 86°, low 71°.
Pressure30.00 inHg
Wind6.3 mph S
Humidity40%
Visibility6.2 mi
Dew point56°
Tue, 1189° / 74°0.05
89 °
Islandia, Tuesday, 11 August
Light rain. High 89°, low 74°.
Pressure29.80 inHg
Wind7.3 mph NW
Humidity52%
Visibility6.2 mi
Dew point64°
Wed, 1281° / 72°0
81 °
Islandia, Wednesday, 12 August
Overcast. High 81°, low 72°.
Pressure29.74 inHg
Wind7.3 mph SE
Humidity54%
Visibility6.2 mi
Dew point61°
Thu, 1384° / 70°0.14
84 °
Islandia, Thursday, 13 August
Light rain. High 84°, low 70°.
Pressure29.71 inHg
Wind13.6 mph NW
Humidity53%
Visibility—
Dew point61°
Fri, 1476° / 65°0
76 °
Islandia, Friday, 14 August
Clear. High 76°, low 65°.
Pressure29.97 inHg
Wind16.3 mph NW
Humidity42%
Visibility—
Dew point45°
Sat, 1579° / 64°0
79 °
Islandia, Saturday, 15 August
Clear. High 79°, low 64°.
Pressure30.06 inHg
Wind14.2 mph NW
Humidity42%
Visibility—
Dew point45°
Sun, 1680° / 66°0
80 °
Islandia, Sunday, 16 August
Overcast. High 80°, low 66°.
Pressure30.12 inHg
Wind8.9 mph N
Humidity35%
Visibility—
Dew point45°
Mon, 1779° / 69°0.01
79 °
Islandia, Monday, 17 August
Light rain. High 79°, low 69°.
Pressure30.03 inHg
Wind10.1 mph SW
Humidity47%
Visibility—
Dew point53°
Tue, 1880° / 68°0.02
80 °
Islandia, Tuesday, 18 August
Light rain. High 80°, low 68°.
Pressure30.03 inHg
Wind8.9 mph S
Humidity46%
Visibility—
Dew point55°
Wed, 1981° / 71°0.02
81 °
Islandia, Wednesday, 19 August
Light rain. High 81°, low 71°.
Pressure30.12 inHg
Wind8.6 mph SE
Humidity52%
Visibility—
Dew point60°
Thu, 2082° / 71°0
82 °
Islandia, Thursday, 20 August
Clear. High 82°, low 71°.
Pressure30.06 inHg
Wind9.3 mph S
Humidity57%
Visibility—
Dew point63°
Fri, 2183° / 74°0.2
83 °
Islandia, Friday, 21 August
Rain. High 83°, low 74°.
Pressure29.91 inHg
Wind14.5 mph S
Humidity57%
Visibility—
Dew point64°
Sat, 2288° / 74°0.07
88 °
Islandia, Saturday, 22 August
Light rain. High 88°, low 74°.
Pressure29.88 inHg
Wind11.9 mph SW
Humidity60%
Visibility—
Dew point68°
Sun, 2386° / 74°0
86 °
Islandia, Sunday, 23 August
Clear. High 86°, low 74°.
Pressure29.94 inHg
Wind6.6 mph SW
Humidity43%
Visibility—
Dew point58°
Mon, 2485° / 77°0.11
85 °
Islandia, Monday, 24 August
Light rain. High 85°, low 77°.
Pressure29.97 inHg
Wind10.3 mph E
Humidity65%
Visibility—
Dew point70°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2578° / 67°0.08
78 °
Islandia, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high78°
Average low67°
Average precipitation0.08 in
Chance of precipitation27%
Record high91° (2020)
Record low58° (1963)
Wed, 2679° / 67°0.08
79 °
Islandia, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high79°
Average low67°
Average precipitation0.08 in
Chance of precipitation22%
Record high89° (2021)
Record low59° (1963)
Thu, 2779° / 68°0.12
79 °
Islandia, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high79°
Average low68°
Average precipitation0.12 in
Chance of precipitation28%
Record high92° (2020)
Record low58° (1969)
Fri, 2879° / 68°0.19
79 °
Islandia, Friday, 28 August
Climate normal for this date — 60-year average.
Average high79°
Average low68°
Average precipitation0.19 in
Chance of precipitation33%
Record high91° (2018)
Record low58° (1986)
Sat, 2978° / 67°0.14
78 °
Islandia, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high78°
Average low67°
Average precipitation0.14 in
Chance of precipitation33%
Record high92° (2018)
Record low52° (1982)
Sun, 3078° / 67°0.07
78 °
Islandia, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high78°
Average low67°
Average precipitation0.07 in
Chance of precipitation27%
Record high90° (1973)
Record low54° (1965)
Mon, 3178° / 67°0.05
78 °
Islandia, Monday, 31 August
Climate normal for this date — 60-year average.
Average high78°
Average low67°
Average precipitation0.05 in
Chance of precipitation18%
Record high93° (2010)
Record low55° (1976)
Tue, 0177° / 66°0.07
77 °
Islandia, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high77°
Average low66°
Average precipitation0.07 in
Chance of precipitation27%
Record high91° (2010)
Record low55° (2017)
Wed, 0276° / 65°0.17
76 °
Islandia, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high76°
Average low65°
Average precipitation0.17 in
Chance of precipitation28%
Record high90° (1966)
Record low56° (2017)
Thu, 0376° / 66°0.11
76 °
Islandia, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high76°
Average low66°
Average precipitation0.11 in
Chance of precipitation28%
Record high87° (2023)
Record low55° (1967)
Fri, 0477° / 66°0.13
77 °
Islandia, Friday, 4 September
Climate normal for this date — 60-year average.
Average high77°
Average low66°
Average precipitation0.13 in
Chance of precipitation25%
Record high89° (2018)
Record low55° (1997)
Sat, 0576° / 65°0.05
76 °
Islandia, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high76°
Average low65°
Average precipitation0.05 in
Chance of precipitation18%
Record high91° (2023)
Record low56° (2000)
Sun, 0676° / 65°0.15
76 °
Islandia, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high76°
Average low65°
Average precipitation0.15 in
Chance of precipitation33%
Record high92° (2023)
Record low55° (1984)
Mon, 0776° / 65°0.08
76 °
Islandia, Monday, 7 September
Climate normal for this date — 60-year average.
Average high76°
Average low65°
Average precipitation0.08 in
Chance of precipitation33%
Record high92° (2023)
Record low55° (1984)
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 Islandia, 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 Islandia, 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.