colorado frost dates, county by county.

Adams County

Last spring: 05-02 · First fall: 10-10

Alamosa County

Last spring: 05-16 · First fall: 09-27

Arapahoe County

Last spring: 05-02 · First fall: 10-10

Archuleta County

Last spring: 05-23 · First fall: 09-30

Baca County

Last spring: 04-24 · First fall: 10-19

Bent County

Last spring: 04-18 · First fall: 10-21

Boulder County

Last spring: 06-04 · First fall: 09-14

Broomfield County

Last spring: 04-20 · First fall: 10-21

Chaffee County

Last spring: 05-15 · First fall: 10-02

Cheyenne County

Last spring: 04-28 · First fall: 10-14

Clear Creek County

Last spring: 05-15 · First fall: 09-30

Conejos County

Last spring: 05-13 · First fall: 09-29

Costilla County

Last spring: 05-13 · First fall: 09-30

Crowley County

Last spring: 04-23 · First fall: 10-16

Custer County

Last spring: 05-28 · First fall: 09-20

Delta County

Last spring: 04-25 · First fall: 10-19

Denver County

Last spring: 04-22 · First fall: 10-18

Dolores County

Last spring: 05-02 · First fall: 10-19

Douglas County

Last spring: 05-01 · First fall: 10-12

Eagle County

Last spring: 05-31 · First fall: 09-21

El Paso County

Last spring: 04-24 · First fall: 10-16

Elbert County

Last spring: 05-02 · First fall: 10-11

Fremont County

Last spring: 04-26 · First fall: 10-17

Garfield County

Last spring: 05-09 · First fall: 10-04

Gilpin County

Last spring: 05-21 · First fall: 09-26

Grand County

Last spring: 05-26 · First fall: 09-20

Gunnison County

Last spring: 06-04 · First fall: 09-17

Hinsdale County

Last spring: 05-31 · First fall: 09-23

Huerfano County

Last spring: 04-29 · First fall: 10-15

Jackson County

Last spring: — · First fall: —

Jefferson County

Last spring: 05-09 · First fall: 10-02

Kiowa County

Last spring: 04-19 · First fall: 10-21

Kit Carson County

Last spring: 04-27 · First fall: 10-19

La Plata County

Last spring: 05-07 · First fall: 10-12

Lake County

Last spring: 06-12 · First fall: 09-10

Larimer County

Last spring: 06-06 · First fall: 09-14

Las Animas County

Last spring: 04-23 · First fall: 10-18

Lincoln County

Last spring: 05-01 · First fall: 10-10

Logan County

Last spring: 04-18 · First fall: 10-18

Mesa County

Last spring: 04-08 · First fall: 11-01

Mineral County

Last spring: 06-11 · First fall: 09-13

Moffat County

Last spring: 06-01 · First fall: 09-19

Montezuma County

Last spring: 04-30 · First fall: 10-17

Montrose County

Last spring: 05-11 · First fall: 10-08

Morgan County

Last spring: 04-27 · First fall: 10-15

Otero County

Last spring: 04-29 · First fall: 10-11

Ouray County

Last spring: 05-26 · First fall: 09-23

Park County

Last spring: 06-15 · First fall: 09-08

Phillips County

Last spring: 05-01 · First fall: 10-12

Pitkin County

Last spring: 05-13 · First fall: 10-02

Prowers County

Last spring: 04-21 · First fall: 10-21

Pueblo County

Last spring: 04-18 · First fall: 10-18

Rio Blanco County

Last spring: 05-21 · First fall: 09-27

Rio Grande County

Last spring: 05-30 · First fall: 09-23

Routt County

Last spring: 05-20 · First fall: 09-23

Saguache County

Last spring: 05-04 · First fall: 10-08

San Juan County

Last spring: 06-22 · First fall: 09-09

San Miguel County

Last spring: 05-11 · First fall: 10-08

Sedgwick County

Last spring: 04-27 · First fall: 10-16

Summit County

Last spring: 06-18 · First fall: 09-06

Teller County

Last spring: 05-14 · First fall: 10-04

Washington County

Last spring: 04-30 · First fall: 10-15

Weld County

Last spring: 05-03 · First fall: 10-05

Yuma County

Last spring: 04-29 · First fall: 10-15