AlaskaNatural lake, 3,558 acres, Kenai Peninsula Borough
Big Johnstone Lake wind forecast
7-day outlook
Daylight hours, 8am to 7pm local time. Wind in knots.
-
MonOct 26
2-7kt
NW, gusts 10
High 45°F, rain 5%
Good -
TueOct 27
1-2kt
NNE, gusts 2
High 48°F, rain 0%
Light wind -
WedOct 28
3-4kt
ENE, gusts 5
High 46°F, rain 68%
Light wind -
ThuOct 29
6-10kt
ENE, gusts 15
High 46°F, rain 95%
Good -
FriOct 30
8-11kt
SSE, gusts 17
High 47°F, rain 97%
Good -
SatOct 31
4-5kt
E, gusts 8
High 43°F, rain 81%
Use caution -
SunNov 1
4-5kt
NE, gusts 7
High 42°F, rain 57%
Use caution
Hour by hour, next 3 days
This week on Big Johnstone
Over the next 7 days on Big Johnstone Lake, the windiest stretch looks like Friday, with gusts to about 17 kt. Tuesday is the calmest day in the outlook, topping out near 2 kt.
Thursday is the pick for sailing, and Tuesday looks best for kayaks and paddleboards. Mornings are usually calmer than afternoons, so check the hourly strip for the exact window.
Reading a lake wind forecast
Sustained wind is the average over a couple of minutes; gusts are the short peaks. On inland water the gap between the two matters as much as the average. A steady 12 kt is a pleasant sail, while 8 kt gusting 20 kt knocks small boats flat and tires out paddlers.
On a lake the size of Big Johnstone, waves stay modest, but nearby hills, trees and buildings bend the wind. Expect shifts and puffs, especially close to shore, and treat the forecast speed as an average across open water.
The National Weather Service forecast covers a 2.5 km grid, so local effects like a sea breeze off a big lake, a cold front or afternoon thunderstorms can arrive earlier or stronger than shown. Check the forecast again on the morning you go, and keep an eye on small craft advisories.
Big Johnstone Lake forecast questions
What is the wind forecast for Big Johnstone Lake this weekend?
In the National Weather Service forecast from October 25: Saturday: E wind 4 to 5 kt, gusts to 8 kt, high near 43°F, 81% chance of rain. Sunday: NE wind 4 to 5 kt, gusts to 7 kt, high near 42°F, 57% chance of rain. The live cards above always show the latest update.
When is the best day to sail on Big Johnstone Lake this week?
Based on the National Weather Service forecast from October 25, Thursday looks best, with ENE wind around 6 to 10 kt and gusts near 15 kt. Forecasts beyond three days shift, so check the live day cards above and look again the night before.
Where does the Big Johnstone Lake wind forecast come from?
From the National Weather Service gridded forecast for the 2.5 km cell over the lake. It is the same forecast local NWS offices use, updated several times a day. We convert wind to knots and add our own go or no-go call for each activity.
What wind is too strong for a kayak or paddleboard?
We flag paddling as risky once sustained wind passes about 8 kt or gusts pass 12 kt, and advise staying ashore above 12 kt sustained or 18 kt gusts. Offshore wind is the most dangerous because it pushes you away from the launch.
Nearby lakes
If Big Johnstone is blown out, these are the closest alternatives. Tap through for their wind forecasts.