Lewiston weather in May: Lewiston, Idaho: normal highs, lows, rain and records for May
Lewiston in May has a normal high of 72°F and a normal low of 48°F, a daily mean of 60°F, rising from 67°F on the 1st to 75°F by the 31st. Measurable precipitation falls on 11 days in a normal May, 1.69 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 22°C and low of 9°C, 43 mm of precipitation in May.
- NOAA stationLewiston Airport
- Station IDUSW00024149
- Location46.37°N 117.02°W
- Elevation1,436 ft (438 m)
- Population34,693
- Jan 42° 30°
- Feb 47° 32°
- Mar 55° 36°
- Apr 62° 41°
- May 72° 48°
- Jun 79° 54°
- Jul 91° 61°
- Aug 90° 60°
- Sep 80° 52°
- Oct 63° 42°
- Nov 49° 35°
- Dec 41° 30°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Lewiston in May?
The normal high is 72°F and the normal low 48°F, for a daily mean of 60.0°F. May is 8.5°F warmer than April and 6.5°F cooler than June. May is the 5th warmest month of the year in Lewiston and the wettest. Across the month the normal high rises 8°F, from 67°F on May 1 to 75°F on May 31. From one year to the next May's mean temperature typically moves about 2.7°F either way (NOAA's standard deviation), so roughly two Mays in three average between 57°F and 63°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 35%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 67°F | 44°F | 34% | 17% |
| May 8 | 70°F | 46°F | 34% | 17% |
| May 15 | 72°F | 48°F | 34% | 18% |
| May 22 | 74°F | 50°F | 35% | 18% |
| May 31 | 75°F | 51°F | 34% | 17% |
Every day of May: normal high, low and chance of precipitation (warmest afternoon May 31, coldest night May 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| May 1 | 67°F | 44°F | 34% | 17% | 14 h 20 min |
| May 2 | 68°F | 44°F | 34% | 17% | 14 h 20 min |
| May 3 | 68°F | 45°F | 34% | 17% | 14 h 30 min |
| May 4 | 69°F | 45°F | 34% | 17% | 14 h 30 min |
| May 5 | 69°F | 45°F | 34% | 17% | 14 h 30 min |
| May 6 | 69°F | 46°F | 34% | 17% | 14 h 30 min |
| May 7 | 70°F | 46°F | 34% | 17% | 14 h 40 min |
| May 8 | 70°F | 46°F | 34% | 17% | 14 h 40 min |
| May 9 | 70°F | 46°F | 34% | 17% | 14 h 40 min |
| May 10 | 71°F | 47°F | 34% | 18% | 14 h 40 min |
| May 11 | 71°F | 47°F | 34% | 18% | 14 h 50 min |
| May 12 | 71°F | 47°F | 34% | 18% | 14 h 50 min |
| May 13 | 72°F | 48°F | 34% | 18% | 14 h 50 min |
| May 14 | 72°F | 48°F | 34% | 18% | 14 h 50 min |
| May 15 | 72°F | 48°F | 34% | 18% | 15 h |
| May 16 | 72°F | 48°F | 35% | 18% | 15 h |
| May 17 | 73°F | 49°F | 35% | 18% | 15 h |
| May 18 | 73°F | 49°F | 35% | 18% | 15 h |
| May 19 | 73°F | 49°F | 35% | 18% | 15 h 10 min |
| May 20 | 73°F | 49°F | 35% | 18% | 15 h 10 min |
| May 21 | 74°F | 50°F | 35% | 18% | 15 h 10 min |
| May 22 | 74°F | 50°F | 35% | 18% | 15 h 10 min |
| May 23 | 74°F | 50°F | 35% | 18% | 15 h 20 min |
| May 24 | 74°F | 50°F | 35% | 18% | 15 h 20 min |
| May 25 | 74°F | 50°F | 35% | 18% | 15 h 20 min |
| May 26 | 75°F | 51°F | 34% | 18% | 15 h 20 min |
| May 27 | 75°F | 51°F | 34% | 18% | 15 h 20 min |
| May 28 | 75°F | 51°F | 34% | 18% | 15 h 20 min |
| May 29 | 75°F | 51°F | 34% | 17% | 15 h 30 min |
| May 30 | 75°F | 51°F | 34% | 17% | 15 h 30 min |
| May 31 | 75°F | 51°F | 34% | 17% | 15 h 30 min |
- Normal high
- 72°FMay average
- Normal low
- 48°FMay average
- Precipitation
- 1.69 inmonth total
- Days with precipitation
- 110.01 inch or more
- Days at 90°F or more
- 1
- Daylight
- 14 h 20 min to 15 h 30 minMay 1 to May 31
- Days at 70°F or more
- 18
- Days at 80°F or more
- 7
- Sunshine
- 75%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024149; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Lewiston in May?
On a given May day the chance of 0.01 inch or more is 34% on average, highest around May 18 (35%). In all, 1.69 in falls on 11 days of a normal May.
In a normal May in Lewiston, 1 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024149.
How humid and windy is Lewiston in May?
At 3 p.m. the normal temperature is 73°F with 35% relative humidity and a dew point of 44°F; at 6 a.m. it is 56°F with 70% humidity. The wind averages 5.4 mph, most often from the north-northwest in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 56°F | 46°F | 70% | 3.6 mph | 62% |
| 9 a.m. | 64°F | 47°F | 53% | 4.8 mph | 62% |
| noon | 71°F | 45°F | 40% | 6.3 mph | 61% |
| 3 p.m. | 73°F | 44°F | 35% | 7.9 mph | 62% |
| 6 p.m. | 71°F | 44°F | 38% | 7.7 mph | 63% |
| 9 p.m. | 63°F | 46°F | 55% | 5.5 mph | 64% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024149. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for May in Lewiston?
The warmest May temperature on Lewiston's official record (since 1881) is 104°F, on May 28, 1934; the coldest is 23°F, on May 1, 1954. The wettest May brought 4.80 in (1948).
The May mean against the 1991-2020 normal of 60.0°F: 2021 61.3°F (+1.3), 2022 56.1°F (−3.9), 2023 66.6°F (+6.6), 2024 59.8°F (−0.2), 2025 62.1°F (+2.1), 2026 62.5°F (+2.5). 4 of 6 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 61.3°F | +1.3°F | 0.16 in |
| 2022 | 56.1°F | −3.9°F | 1.91 in |
| 2023 | 66.6°F | +6.6°F | 0.71 in |
| 2024 | 59.8°F | −0.2°F | 0.79 in |
| 2025 | 62.1°F | +2.1°F | 0.51 in |
| 2026 | 62.5°F | +2.5°F | 0.77 in |
Source: records: ACIS, NWS threaded record LWSthr; recent months: ACIS, station USW00024149. Records and recent months use complete months only.
How does May in Lewiston compare across Idaho?
Across the 85 places PlainClimate covers in Idaho, May normal highs run from 50°F in Mullan to 79°F in Glenns Ferry; Lewiston's is 72°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.