Lewis and Clark County (Helena)
May
Weather in Lewis and Clark County, Montana for May 2027
Your guide to Lewis and Clark County weather in May - trends and predictions
Lewis and Clark County experiences moderate rainfall in May, with an average of 10 rainy days and a total precipitation of 69.6 mm.
Is May a good time to visit Lewis and Clark County? check out the best time to travel to Lewis and Clark County page.
✨ Is May a good time to visit Lewis and Clark County? – Ask the AI Weatherman
Rain 🌧️
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21
Dry days
10
Rainy days
0
Snow days
19°/5°
Temperatures
17 km/h
Avg max wind
55 %
Avg humidity
Lewis and Clark County Weather May
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Temperatures trend during May in Lewis and Clark County
See the weather trend as well as the moving average line
May weather in Lewis and Clark County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| May 1 |  Sunny | 19° /1° | 0 mm | 6 | |
| May 2 | Sunny | 21° /3° | 0 mm | 7 | |
| May 3 | Sunny | 22° /4° | 0 mm | 7 | |
| May 4 |  Light rain | 14° /4° | 4.9 mm | 5 | |
| May 5 |  Moderate or heavy rain shower | 9° /1° | 6.7 mm | 5 | |
| May 6 |  Overcast | 17° /-2° | 0.2 mm | 6 | |
| May 7 |  Cloudy | 19° /4° | 0.6 mm | 6 | |
| May 8 | Sunny | 21° /5° | 0 mm | 7 | |
| May 9 |  Partly cloudy | 21° /6° | 0 mm | 7 | |
| May 10 |  Patchy rain possible | 26° /7° | 0.8 mm | 7 | |
| May 11 | Overcast | 23° /9° | 0 mm | 7 | |
| May 12 | Patchy rain possible | 22° /7° | 0.9 mm | 6 | |
| May 13 | Light rain | 20° /8° | 3.9 mm | 5 | |
| May 14 | Moderate or heavy rain shower | 14° /7° | 8.6 mm | 6 | |
| May 15 | Moderate or heavy rain shower | 13° /5° | 5.7 mm | 6 | |
| May 16 | Patchy rain possible | 12° /3° | 1.5 mm | 3 | |
| May 17 | Overcast | 11° /2° | 0.9 mm | 3 | |
| May 18 | Light rain | 11° /2° | 2.5 mm | 6 | |
| May 19 | Partly cloudy | 16° /1° | 0.1 mm | 7 | |
| May 20 | Light rain | 15° /2° | 5.3 mm | 4 | |
| May 21 | Patchy rain possible | 14° /1° | 0.5 mm | 3 | |
| May 22 | Patchy rain possible | 17° /3° | 1.7 mm | 7 | |
| May 23 | Patchy rain possible | 20° /4° | 2 mm | 7 | |
| May 24 | Sunny | 22° /6° | 0 mm | 6 | |
| May 25 | Sunny | 25° /6° | 0 mm | 8 | |
| May 26 | Sunny | 26° /7° | 0.8 mm | 8 | |
| May 27 |  Thundery outbreaks possible | 24° /10° | 0.3 mm | 6 | |
| May 28 | Sunny | 26° /9° | 0.1 mm | 8 | |
| May 29 | Light rain | 27° /9° | 7.5 mm | 8 | |
| May 30 |  Moderate rain | 19° /10° | 11.6 mm | 7 | |
| May 31 | Light rain | 22° /7° | 2.9 mm | 7 | |
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Important Notice
Our weather forecast for Lewis and Clark County in May is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Lewis and Clark County forecast closer to your planned date for the most up-to-date weather information.
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Lewis and Clark County in May - FAQ
What are the expected maximum and minimum temperatures in Lewis and Clark County during May?
Enjoy moderate daytime temperatures of up to 19° and cooler nights around 5°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Lewis and Clark County during May?
Moderate rainfall is anticipated in Lewis and Clark County during May, with a total of 69.6 mm spread over approximately 10 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Lewis and Clark County during May?
The average wind speed in Lewis and Clark County during May is 17 km/h, suggesting breezy to windy conditions, depending on your activities.
May rainfall patterns in Lewis and Clark County
Explore the daily rainfall trends and prepare for Lewis and Clark Countys May weather 💧
Typically, Lewis and Clark County has 10 rainy days in May with a total of 69.6 mm of rainfall.
UV exposure in Lewis and Clark County during May
Stay informed about UV levels for safe outdoor activities throughout the month of May ☀️
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