FPUS55 KBOI 182031 ZFPBOI Zone Forecasts for Southwest Idaho/Southeast Oregon National Weather Service Boise ID 230 PM MDT Mon May 18 2026 Spot temperatures are for tonight, Tuesday, Tuesday night, and Wednesday. IDZ011-190400- West Central Mountains- 230 PM MDT Mon May 18 2026 .TONIGHT...Partly cloudy with a slight chance of rain and snow showers this evening, then mostly clear after midnight. Chance of precipitation 20 percent. Lows 28 to 38. .TUESDAY...Sunny. Highs 52 to 66. .TUESDAY NIGHT...Partly cloudy. Lows 33 to 43. .WEDNESDAY...Partly sunny. Highs 54 to 69. .WEDNESDAY NIGHT...Partly cloudy in the evening, then clearing. Areas of fog after midnight. Lows 34 to 44. .THURSDAY...Areas of fog in the morning. Sunny. Highs 58 to 72. .THURSDAY NIGHT...Partly cloudy. Lows 35 to 45. .FRIDAY AND FRIDAY NIGHT...Mostly clear. Highs 60 to 74. Lows 37 to 47. .SATURDAY...Sunny. Highs 65 to 79. .SATURDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 41 to 51. .SUNDAY...Sunny. Highs 66 to 80. .SUNDAY NIGHT...Increasing clouds. Lows 41 to 51. .MEMORIAL DAY...Partly cloudy with a 20 percent chance of rain showers. Highs 61 to 74. && TEMPERATURE McCall 29 61 33 64 $$ = IDZ013-190400- Boise Mountains- 230 PM MDT Mon May 18 2026 .TONIGHT...Partly cloudy this evening, then clearing. Lows 24 to 39. Breezy. .TUESDAY...Sunny. Highs 54 to 68. .TUESDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 27 to 42. .WEDNESDAY...Mostly sunny. Highs 58 to 72. .WEDNESDAY NIGHT...Decreasing clouds. Lows 29 to 44. .THURSDAY...Sunny. Highs 61 to 76. .THURSDAY NIGHT...Increasing clouds. Lows 31 to 46. .FRIDAY AND FRIDAY NIGHT...Mostly clear. Highs 63 to 78. Lows 33 to 48. .SATURDAY THROUGH SUNDAY NIGHT...Mostly clear. Highs 70 to 85. Lows 38 to 53. .MEMORIAL DAY...Mostly sunny. Highs 66 to 80. && TEMPERATURE Idaho City 29 67 33 71 $$ = IDZ028-190400- Camas Prairie- 230 PM MDT Mon May 18 2026 .TONIGHT...Mostly cloudy this evening, then clearing. Lows 27 to 32. North winds 10 to 15 mph with gusts to 25 mph this evening, becoming light after midnight. .TUESDAY...Sunny. Highs 59 to 64. Light winds in the morning, becoming southwest 10 to 15 mph in the afternoon. .TUESDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 29 to 34. West winds 10 to 15 mph in the evening, becoming light after midnight. .WEDNESDAY...Increasing clouds. Highs 64 to 69. Light winds in the morning, becoming west 10 to 15 mph with gusts to 25 mph in the afternoon. .WEDNESDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 32 to 37. Breezy. Northwest winds 10 to 20 mph. .THURSDAY THROUGH FRIDAY NIGHT...Mostly clear. Highs 66 to 73. Lows 33 to 40. .SATURDAY THROUGH MEMORIAL DAY...Mostly clear. Highs 74 to 82. Lows 38 to 45. Windy. && TEMPERATURE Fairfield 27 62 29 67 $$ = IDZ033-190400- Upper Weiser River- 230 PM MDT Mon May 18 2026 .TONIGHT...Decreasing clouds. Lows 37 to 42. Breezy. North winds 10 to 20 mph with gusts to 30 mph this evening, decreasing to around 10 mph after midnight. .TUESDAY...Sunny. Highs 65 to 71. Light winds. .TUESDAY NIGHT...Partly cloudy. Lows 41 to 46. North winds up to 10 mph. .WEDNESDAY...Mostly sunny. Highs 68 to 75. Light winds. .WEDNESDAY NIGHT...Mostly clear. Lows 43 to 48. North winds 10 to 15 mph. .THURSDAY...Sunny. Highs 72 to 78. .THURSDAY NIGHT...Increasing clouds. Lows 44 to 49. .FRIDAY AND FRIDAY NIGHT...Mostly clear. Highs 73 to 80. Lows 46 to 51. .SATURDAY...Sunny. Highs 79 to 85. .SATURDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 49 to 54. .SUNDAY...Sunny. Highs 80 to 86. .SUNDAY NIGHT AND MEMORIAL DAY...Partly cloudy. Lows 49 to 54. Highs 73 to 79. && TEMPERATURE Council 39 69 42 72 Cambridge 37 71 42 75 $$ = ORZ064-190400- Oregon Lower Treasure Valley- 230 PM MDT Mon May 18 2026 /130 PM PDT Mon May 18 2026/ .TONIGHT...Partly cloudy this evening, then clearing. Lows 40 to 45. Northwest winds 10 to 15 mph. .TUESDAY...Sunny. Highs 71 to 76. Light winds. .TUESDAY NIGHT...Partly cloudy. Lows 43 to 48. Light winds in the evening, becoming northwest up to 10 mph after midnight. .WEDNESDAY...Mostly sunny. Highs 73 to 78. Light winds. .WEDNESDAY NIGHT...Mostly clear. Lows 46 to 51. North winds 10 to 15 mph with gusts to 25 mph. .THURSDAY...Sunny. Highs 76 to 81. .THURSDAY NIGHT...Increasing clouds. Lows 47 to 52. .FRIDAY AND FRIDAY NIGHT...Mostly clear. Highs 78 to 83. Lows 48 to 53. .SATURDAY...Sunny. Highs 83 to 88. .SATURDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 53 to 58. .SUNDAY...Sunny. Highs 85 to 90. .SUNDAY NIGHT AND MEMORIAL DAY...Partly cloudy. Lows 51 to 56. Highs 78 to 83. && TEMPERATURE Ontario 41 74 44 76 $$ = IDZ012-190400- Lower Treasure Valley- 230 PM MDT Mon May 18 2026 .TONIGHT...Decreasing clouds. Lows 39 to 44. Northwest winds 10 to 15 mph. Gusts to 25 mph this evening. .TUESDAY...Sunny. Highs 70 to 75. Northwest winds up to 10 mph. .TUESDAY NIGHT...Increasing clouds. Lows 42 to 47. Light winds. .WEDNESDAY...Mostly sunny. Highs 73 to 78. Northwest winds up to 10 mph. .WEDNESDAY NIGHT...Mostly clear. Lows 45 to 50. North winds 10 to 15 mph. .THURSDAY THROUGH FRIDAY NIGHT...Mostly clear. Highs 75 to 83. Lows 45 to 52. .SATURDAY...Sunny. Highs 84 to 89. .SATURDAY NIGHT...Decreasing clouds. Lows 52 to 57. .SUNDAY...Sunny. Highs 85 to 90. .SUNDAY NIGHT AND MEMORIAL DAY...Partly cloudy. Lows 50 to 55. Highs 79 to 84. && TEMPERATURE Caldwell 40 73 43 76 $$ = IDZ014-190400- Upper Treasure Valley- 230 PM MDT Mon May 18 2026 .TONIGHT...Partly cloudy this evening, then clearing. Lows 36 to 41. Breezy. Northwest winds 10 to 20 mph with gusts to 30 mph this evening, decreasing to around 10 mph after midnight. .TUESDAY...Sunny. Highs 69 to 74. Northwest winds up to 10 mph with gusts to 20 mph. .TUESDAY NIGHT...Partly cloudy. Lows 38 to 45. North winds around 10 mph in the evening, becoming light after midnight. Gusts to 20 mph. .WEDNESDAY...Mostly sunny. Highs 73 to 78. Light winds in the morning, becoming northwest around 10 mph in the afternoon. Gusts to 20 mph. .WEDNESDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 42 to 47. Northwest winds 10 to 15 mph with gusts to 25 mph. .THURSDAY THROUGH FRIDAY NIGHT...Mostly clear. Highs 75 to 83. Lows 42 to 50. Breezy. .SATURDAY THROUGH MEMORIAL DAY...Mostly clear. Highs 82 to 92. Lows 49 to 55. Breezy. && TEMPERATURE Boise 41 71 45 74 Mountain Home 36 72 39 76 $$ = IDZ016-190400- Western Magic Valley- 230 PM MDT Mon May 18 2026 ...FROST ADVISORY IN EFFECT FROM 4 AM TO 8 AM MDT TUESDAY... .TONIGHT...Mostly cloudy this evening, then clearing. Lows 33 to 38. West winds 10 to 15 mph with gusts to 25 mph this evening, shifting to southeast after midnight. .TUESDAY...Patchy frost in the morning. Sunny. Highs 65 to 70. South winds around 10 mph in the morning, shifting to west in the afternoon. .TUESDAY NIGHT...Decreasing clouds. Lows 36 to 41. West winds around 10 mph in the evening, shifting to southeast after midnight. Gusts to 20 mph. .WEDNESDAY...Mostly sunny. Highs 70 to 75. Southeast winds up to 10 mph in the morning, shifting to west in the afternoon. .WEDNESDAY NIGHT...Decreasing clouds. Lows 41 to 46. West winds 10 to 15 mph. Gusts to 25 mph in the evening. .THURSDAY THROUGH FRIDAY NIGHT...Mostly clear. Highs 71 to 79. Lows 40 to 47. .SATURDAY THROUGH MEMORIAL DAY...Mostly clear. Highs 80 to 88. Lows 47 to 53. Breezy. && TEMPERATURE Jerome 35 66 39 72 Twin Falls 36 66 39 71 $$ = IDZ029-190400- Owyhee Mountains- 230 PM MDT Mon May 18 2026 .TONIGHT...Partly cloudy this evening, then clearing. Lows 33 to 42. .TUESDAY...Sunny. Highs 62 to 67. .TUESDAY NIGHT...Increasing clouds. Lows 37 to 46. .WEDNESDAY...Mostly sunny. Highs 65 to 70. .WEDNESDAY NIGHT...Partly cloudy. Lows 39 to 48. .THURSDAY...Sunny. Highs 67 to 72. Breezy. .THURSDAY NIGHT...Increasing clouds. Lows 40 to 50. .FRIDAY AND FRIDAY NIGHT...Mostly clear. Highs 70 to 75. Lows 43 to 52. .SATURDAY...Sunny. Highs 76 to 81. .SATURDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 47 to 57. .SUNDAY...Sunny. Highs 78 to 83. .SUNDAY NIGHT AND MEMORIAL DAY...Partly cloudy. Lows 47 to 55. Highs 72 to 78. $$ = IDZ015-190400- Southwest Highlands- 230 PM MDT Mon May 18 2026 .TONIGHT...Partly cloudy this evening, then clearing. Lows 31 to 37. Breezy. .TUESDAY...Sunny. Highs 60 to 68. .TUESDAY NIGHT...Partly cloudy. Lows 35 to 40. .WEDNESDAY...Mostly sunny. Highs 66 to 73. .WEDNESDAY NIGHT...Decreasing clouds. Lows 39 to 44. .THURSDAY AND THURSDAY NIGHT...Mostly clear. Highs 68 to 75. Lows 39 to 44. Breezy. .FRIDAY...Mostly sunny. Highs 71 to 78. .FRIDAY NIGHT AND SATURDAY...Mostly clear. Lows 41 to 47. Highs 77 to 84. .SATURDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 45 to 52. .SUNDAY...Sunny. Highs 81 to 87. .SUNDAY NIGHT...Decreasing clouds. Lows 45 to 51. .MEMORIAL DAY...Sunny. Highs 78 to 83. $$ = IDZ030-190400- Southern Twin Falls County- 230 PM MDT Mon May 18 2026 .TONIGHT...Partly cloudy this evening, then clearing. Lows 32 to 37. .TUESDAY...Sunny. Highs 61 to 66. .TUESDAY NIGHT...Decreasing clouds. Lows 36 to 41. .WEDNESDAY...Mostly sunny. Highs 68 to 73. .WEDNESDAY NIGHT...Decreasing clouds. Lows 41 to 46. .THURSDAY THROUGH FRIDAY NIGHT...Mostly clear. Highs 68 to 77. Lows 40 to 48. Breezy. .SATURDAY AND SATURDAY NIGHT...Partly cloudy. Highs 78 to 83. Lows 48 to 53. .SUNDAY...Sunny. Highs 82 to 87. .SUNDAY NIGHT...Decreasing clouds. Lows 48 to 53. .MEMORIAL DAY...Sunny. Highs 80 to 85. Breezy. $$ = ORZ062-190400- Baker County- 130 PM PDT Mon May 18 2026 .TONIGHT...Partly cloudy with a slight chance of rain showers this evening, then mostly clear after midnight. Chance of rain 20 percent. Lows 31 to 41. North winds 10 to 15 mph with gusts to 30 mph this evening, becoming light after midnight. .TUESDAY...Sunny. Highs 64 to 71. Northwest winds up to 10 mph. .TUESDAY NIGHT...Partly cloudy. Lows 35 to 45. Northwest winds up to 10 mph. .WEDNESDAY...Mostly sunny. Highs 66 to 74. Northwest winds up to 10 mph. .WEDNESDAY NIGHT...Mostly clear. Lows 36 to 46. Breezy. Northwest winds 10 to 20 mph. Gusts to 40 mph in the evening. .THURSDAY...Sunny. Highs 69 to 77. .THURSDAY NIGHT...Partly cloudy. Lows 38 to 49. .FRIDAY THROUGH SATURDAY...Mostly clear. Highs 73 to 83. Lows 41 to 51. .SATURDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 44 to 54. .SUNDAY...Sunny. Highs 77 to 85. .SUNDAY NIGHT...Partly cloudy. Lows 42 to 52. .MEMORIAL DAY...Partly cloudy with a 20 percent chance of rain showers. Highs 69 to 77. Breezy. && TEMPERATURE Baker City 32 67 35 69 $$ = ORZ061-190400- Harney County- 130 PM PDT Mon May 18 2026 .TONIGHT...Partly cloudy this evening, then clearing. Lows 31 to 38. North winds 10 to 15 mph. .TUESDAY...Sunny. Highs 63 to 70. West winds up to 10 mph. .TUESDAY NIGHT...Increasing clouds. Lows 34 to 42. Northwest winds up to 10 mph. .WEDNESDAY...Mostly sunny. Highs 67 to 74. Northwest winds up to 10 mph. .WEDNESDAY NIGHT...Partly cloudy. Lows 36 to 45. North winds 10 to 15 mph with gusts to 25 mph. .THURSDAY...Sunny. Highs 69 to 77. .THURSDAY NIGHT...Partly cloudy. Lows 38 to 46. .FRIDAY THROUGH SATURDAY...Mostly clear. Highs 72 to 82. Lows 40 to 49. .SATURDAY NIGHT...Decreasing clouds. Lows 42 to 51. .SUNDAY...Sunny. Highs 77 to 84. .SUNDAY NIGHT AND MEMORIAL DAY...Partly cloudy. Lows 40 to 49. Highs 69 to 77. && TEMPERATURE Burns 31 69 34 73 $$ = ORZ063-190400- Malheur County- 230 PM MDT Mon May 18 2026 /130 PM PDT Mon May 18 2026/ .TONIGHT...Partly cloudy this evening, then clearing. Lows 32 to 42. North winds 10 to 15 mph with gusts to 25 mph this evening, becoming light after midnight. .TUESDAY...Sunny. Highs 65 to 72. Northwest winds up to 10 mph. .TUESDAY NIGHT...Partly cloudy. Lows 36 to 46. North winds up to 10 mph in the evening, becoming light after midnight. .WEDNESDAY...Mostly sunny. Highs 69 to 76. North winds up to 10 mph. .WEDNESDAY NIGHT...Partly cloudy. Lows 39 to 49. Breezy. North winds 10 to 20 mph with gusts to 30 mph. .THURSDAY...Sunny. Highs 71 to 78. .THURSDAY NIGHT...Increasing clouds. Lows 40 to 50. .FRIDAY THROUGH SATURDAY...Mostly clear. Highs 76 to 86. Lows 43 to 51. .SATURDAY NIGHT...Partly cloudy in the evening, then clearing. Lows 46 to 55. .SUNDAY...Sunny. Highs 81 to 88. .SUNDAY NIGHT AND MEMORIAL DAY...Partly cloudy. Lows 45 to 53. Highs 74 to 82. $$ =