National Weather Service Forecast for: Siloam Springs AR
Issued by: National Weather Service Tulsa, OK
Updated: 2:50 am CDT Aug 20, 2026
 
Overnight

Overnight: A 20 percent chance of showers and thunderstorms.  Mostly cloudy, with a low around 73. Calm wind.
Slight Chance
T-storms

Thursday

Thursday: Mostly cloudy through mid morning, then gradual clearing, with a high near 98. Heat index values as high as 101. Calm wind becoming north around 5 mph in the afternoon.
Becoming
Sunny

Thursday
Night
Thursday Night: A 20 percent chance of showers after 4am.  Mostly clear, with a low around 71. North wind around 5 mph becoming east after midnight.
Mostly Clear
then Slight
Chance
Showers
Friday

Friday: A 20 percent chance of showers before 10am.  Partly sunny, then gradually becoming sunny, with a high near 99. Heat index values as high as 102. North wind around 5 mph becoming southeast in the morning.
Slight Chance
Showers then
Sunny
Friday
Night
Friday Night: A 20 percent chance of showers after 1am.  Mostly clear, with a low around 73. Calm wind becoming east around 5 mph.
Mostly Clear
then Slight
Chance
Showers
Saturday

Saturday: A slight chance of showers and thunderstorms before 10am, then a slight chance of showers between 10am and 1pm.  Mostly sunny, with a high near 98. South wind around 5 mph becoming west in the afternoon.  Chance of precipitation is 20%.
Slight Chance
T-storms then
Slight Chance
Showers
Saturday
Night
Saturday Night: Mostly clear, with a low around 72. East wind around 5 mph.
Mostly Clear

Sunday

Sunday: Mostly sunny, with a high near 95. Southeast wind around 5 mph.
Mostly Sunny

Sunday
Night
Sunday Night: A 30 percent chance of showers and thunderstorms, mainly after 1am.  Partly cloudy, with a low around 73. Southeast wind 5 to 10 mph.
Slight Chance
T-storms then
Chance
Showers
Lo 73 °F Hi 98 °F Lo 71 °F Hi 99 °F Lo 73 °F Hi 98 °F Lo 72 °F Hi 95 °F Lo 73 °F

Hazardous Weather Outlook
 

Overnight
 
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 73. Calm wind.
Thursday
 
Mostly cloudy through mid morning, then gradual clearing, with a high near 98. Heat index values as high as 101. Calm wind becoming north around 5 mph in the afternoon.
Thursday Night
 
A 20 percent chance of showers after 4am. Mostly clear, with a low around 71. North wind around 5 mph becoming east after midnight.
Friday
 
A 20 percent chance of showers before 10am. Partly sunny, then gradually becoming sunny, with a high near 99. Heat index values as high as 102. North wind around 5 mph becoming southeast in the morning.
Friday Night
 
A 20 percent chance of showers after 1am. Mostly clear, with a low around 73. Calm wind becoming east around 5 mph.
Saturday
 
A slight chance of showers and thunderstorms before 10am, then a slight chance of showers between 10am and 1pm. Mostly sunny, with a high near 98. South wind around 5 mph becoming west in the afternoon. Chance of precipitation is 20%.
Saturday Night
 
Mostly clear, with a low around 72. East wind around 5 mph.
Sunday
 
Mostly sunny, with a high near 95. Southeast wind around 5 mph.
Sunday Night
 
A 30 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 73. Southeast wind 5 to 10 mph.
Monday
 
A 20 percent chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 95. South wind around 10 mph, with gusts as high as 20 mph.
Monday Night
 
Mostly clear, with a low around 74. South wind 5 to 10 mph.
Tuesday
 
Sunny, with a high near 98. South wind 5 to 10 mph becoming west in the afternoon.
Tuesday Night
 
Partly cloudy, with a low around 73. North wind around 5 mph becoming southeast after midnight.
Wednesday
 
A 20 percent chance of showers. Mostly sunny, with a high near 96. Southeast wind around 5 mph becoming northwest in the afternoon.

 

Forecast from NOAA-NWS for Siloam Springs AR.