Lake Sinai, SD climate
Lake Sinai has cold, snowy winters and pleasant summers. A typical July afternoon reaches 82°, a January night drops to 5°, and about 36 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Lake Sinai feels like
Winter
Spring
Summer
Fall
Lake Sinai weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 23° | 5° | 0.6" | 5.5" | 6 | 24 | 2° – 28° |
| February | 28° | 9° | 0.8" | 7.1" | 6 | 18 | 5° – 31° |
| March | 41° | 21° | 1.3" | 6.4" | 7 | 12 | 20° – 46° |
| April | 55° | 32° | 2.6" | 4.1" | 10 | 3 | 34° – 51° |
| May | 68° | 45° | 3.6" | 0.1" | 13 | 0 | 52° – 64° |
| June | 77° | 56° | 4.2" | 0 | 12 | 0 | 62° – 71° |
| July | 82° | 60° | 3.6" | 0 | 10 | 0 | 63° – 78° |
| August | 80° | 58° | 3.3" | 0 | 9 | 0 | 63° – 73° |
| September | 72° | 49° | 2.9" | 0 | 8 | 0 | 54° – 66° |
| October | 58° | 36° | 2.1" | 1.1" | 8 | 1 | 39° – 51° |
| November | 41° | 22° | 1.0" | 4.7" | 5 | 7 | 21° – 42° |
| December | 28° | 11° | 0.8" | 6.8" | 6 | 19 | 5° – 26° |
| Year | 54° | 34° | 26.7" | 35.8" | 99 | 83 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Lake Sinai
Lake Sinai gets 27 inches of rain and melted snow a year. June is the wettest month and January the driest. Rain or snow falls on about 99 days a year. Snow covers the ground about 83 days of the year.
About 151 frost-free days a year
In half of years the last 32° night comes by May 3 and the first one by October 2. That leaves about 151 frost-free days for gardens, shorter than 80% of U.S. towns.
Heating and cooling a home in Lake Sinai
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Lake Sinai, 93% of that work is heating and 7% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Lake Sinai and its neighbors
Lake Sinai borders 4 towns with climate data. January nights across them vary by 0.7°. Spring Lake has the coldest January nights (5°) and Oslo the hottest July afternoons (82°). Lake Sinai’s January low is 5° and its July high 82°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Lake Sinai compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Lake Sinai averaged 0.7° warmer than the 1900s. The biggest change is in January (+2.5°). The shift is smaller than in 92% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Lake Sinai’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. March swings the most: between 1991 and 2020 its average temperature ranged from 20° to 46°. June is the most reliable, staying within 9°.
Common questions about Lake Sinai’s climate
What is the coldest month in Lake Sinai?
January, with a typical high of 23° and a low of 5°.
What is the hottest month in Lake Sinai?
July, with a typical high of 82° and a low of 60°. About 10 days a year reach 90°.
How much snow does Lake Sinai get?
About 36 inches in a normal winter, most of it in February.
When is the first frost in Lake Sinai?
In half of years the first 32° night comes by October 2, and the last spring frost by May 3.
What is the rainiest month in Lake Sinai?
June, with 4.2 inches of rain and melted snow. The year totals 27 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Lake Sinai itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Brookings 2 Ne, SD (15 mi, snow) and Arlington 1 W, SD (11 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.