Star Party Weather
Got a favourite star party? Or maybe you like to travel from one to another? Here's a set of climatological tables that will let you know how the cloudiness shapes up.

Technical details:

These cloud statistics are extracted from data archives at the National Climate Data Center. At each star party site, the closest location for which cloud cover data are available was selected, with due regard for similar topographical positioning and climate influences. The tables are a little unfair to some mountain star parties (both on the east and west coast) where the nearest climate station (usually airports) is not always close to the star party site. Some star party sites and dates also change from year to year, but the most recent information that I could find is included in the tables. Generally, the cloud amounts are 20-year averages ending in 2008.

The cloud data are for midnight, local standard time. The cloud categories are derived from regular hourly observations, which, for historical reasons, are evaluated in eights of sky covered (oktas). Thus "few" is 1 to 2 eights, "scattered" is 3 to 4 eights, "broken" is 5 to 7 eights, and "overcast" is a sky with no breaks at all. Clear requires a completely cloud-free sky. Obscured usually refers to fog, in which the sky is not visible, and partly obscured is the same, but with some transparency or breaks. I treat these categories as overcast. The "average cloud amount" is a statistical combination of the seven categories.

Keeping up with all of the star parties is a big job, and if I've missed your site or have the wrong month, let me know and I'll fix it up. Many of these events change months from year to year, but the cloud cover stats will probably not change much if I'm not up-to-date. And remember - these are climatological averages, not necessarily the weather you will get.

- Jay Anderson

Star Party Weather - Canada
  Midnight Percent Frequency of...  
Name Location
Date
Clear Few Scattered Broken Overcast Obscured Partly obscured Average Cloud Amount
Tuktoyaktuk Star Party Tuktoyaktuk, NWT or substitute January 34.5 9.1 8.7 15.9 30.6 1.2 0 49
Frozen Banana Star Party Munro Park near Powassan, ON May 29.5 15.5 3.9 16.6 32.6 1.8 0 51
Rendez-vous des Observateurs du Ciel Mansonville, QC  May-June 35 16.8 2.6 13 32.2 0.2 0.2 47
Concours Annuel de Fabricants de Télescopes d'Amateurs Valleyfield, QC July 36.9 14.4 11.5 17.7 19.1 0.3 0 41
Gateway to the Universe Star Party Restoule Provincial Park, ON July 24.7 26.4
6.7
19.9 20.9 0.7 0.7 45
StarBQ Eccles Ranch, Caroline, AB July 11.8 35.2 8.9 30 14.1 0 0 47
Stargazing Manitoulin Gordon's Park, Manitoulin Island, ON July 27.8 27.1 5.1 17.5 21.2 0.5 0.8 43
Astro Atlantik Mt. Carleton Prov. Park, NB August 24.6 24.6 0 15 35.3 0 0.5 51
Butterpot Star Party Butterpot Prov Park (36km SW of St.John's, NL) August 11.6 17.8 4.7 18.8 39.9 7.4 0 67
Huronia Star Party Highlands Nordic Centre, Duntroon, ON August 12.4 23.3 0 38.8 21.7 3.9 0 60
Manitoulin Star Party Manitoulin Is., ON August 33.6 21.8 5.4 14.3 23 1.5 0.3 42
Mt. Kobau Star Party Mt Kobau, BC August 37.7 26.5 6.9 17.3 11.2 0 0.3 32
Nova East Smiley's Prov Park, Brooklyn, NS  August 24.1 16.2 5.3 14.5 28.1 11 0.9 56
RASCALS Star Party Malahat, BC August 31.1 29.3 4.2 22.2 13 0.2 0 37
Saskatchewan Summer Star Party Cypress Hills, SK August 25.7 32.7 11.4 14.3 15.8 0 0 37
Starfest River Place Campground, Mount Forrest, ON August 12.4 23.3 0 38.8 21.7 3.9 0 60
Alberta Star Party Drumheller, AB September 29.5 20.2 5.7 20 24.1 0.5 0 46
Annual Algonquin Adventure Algonquin Park, ON September 25.7 21.3 6.3 14.5 30.5 1.4 0.3 50
Fall 'n Stars North of Belleville, ON September 27.8 22.7 4.3 18.7 25.8 0.3 0.3 46
Merritt Star Quest (Fall) Loon Lake Gravel Pit, Merritt, BC September 36.6 18.4 4.8 23.6 16.7 0 0 40
Northern Prairie Starfest Black Nugget Lake, AB  September 15.8 26.3 7.2 28 22.6 0 0.2 52
Spruce Woods Star Party Spruce Woods Prov Park, MB September 42.4 16.2 6.4 13.1 21.5 0.4 0 37
 
Star Party Weather - United States
      Midnight Percent Frequency of...  
Name Location Date Clear Few Scattered Broken Overcast Obscured Partly obscured Average Cloud Amount
Cedar Key Winter Star Party Cedar Key, FL February 41.9 7.6 1.8 11.9 34.3 1.4 1.1 47
Death Valley Star Party Death Valley National Park, CA February 36.8 18.4 3.9 19.7 21.1 0 0 41
Orange Blossom Special Star Party Alafia River State Park southeast of Tampa, FL  February 56 12 8 12 12 0 0 27
Wagman Winterfest  Deer Lakes Regional Park near Russellton, PA February 22.7 8.5 2.7 12.4 52.2 1.6 0 66
Winter Star Party Girl Scout Camp Wesumkee, Florida Keys, FL February 49.1 16.7 9.4 12.4 12.4 0 0 29
All Arizona Messier Marathon Farnsworth Ranch near Arizona City, AZ March 79.5 3.6 3.6 9.2 4 0 0 13
CFAS Astrofest Kissimmee Prairie Preserve March 70 5.4 4 7.9 12.3 0.4 0 21
Hodges Gardens Star Party Hodges Gardens State Park, LA March 54.8 3 4.6 7.6 28.9 1.1 0 38
Kentuckiana Star Gaze and Messier Marathon Taylorsville Lake State Park, KY March 37.6 8 4 12.7 37.4 0.2 0 51
Smoky Mountain Stargaze near Cherokee, NC March 43.1 7.4 4.9 10.1 34.5 0 0 46
Antietam Battlefield Star Party Antietam battlefield near Sharpsburg, MD April 38.7 11.9 3.1 13.1 31.7 1.4 0.2 47
Delmarva Stargaze Tuckahoe State Park, MD April 54.3 0 0 2.9 42.9 0 0 45
Georgia Sky View Party Indian Springs State Park south of Jackson, GA April 32.5 16.2 11.9 17.5 21.9 0 0 43
Mid-South Star Gaze French Camp, MS April 63.3 6.7 2.7 8 19.3 0 0 28
South Jersey Spring Star Party Belleplain State Forest, NJ  April 43.5 11.1 1.8 10 30.7 2.5 0.5 44
Southern Star Astronomy Convention Wildacres near Little Switzerland, NC April 41.5 9.2 5.9 11.7 31.4 0.3 0 45
Tennessee Spring Star Party Fall Creek Falls State Park near Spencer, TN April 44.1 10 1.7 10 32.7 1.4 0.2 44
Texas Star Party Prude Ranch near Fort Davis, TX April 88.1 1.3 1.3 5.7 3.8 0 0 9
WKAA Spring Star Party Pennyrile Forest State Park, KY April 30.6 11.6 12.3 19 26.1 0.4 0 49
Astro Acres Spring Star Party south of Morocco, IN May 22 20.5 1 22.9 33.2 0.5 0 55
Prineville Reservoir Star Party Prineville, OR May 50.9 8.1 4.2 13.7 23.1 0 0 37
Riverside Telescope Makers Conference (RTMC) Astronomy Expo YMCA Camp Oakes near Big Bear City, CA May 48.5 6.1 6.1 21.2 18.2 0 0 38
Southern New Mexico Star Party  City of Rocks State Park, NM May 90.2 0 3 3.8 3 0 0 7
North Dakota Star Party Cross Ranch State Park, ND May-June 54.4 8.3 5.4 7.6 24.4 0 0 34
      Midnight Percent Frequency of...  
Name Location Date Clear Few Scattered Broken Overcast Obscured Partly obscured Average Cloud Amount
AOS Starfest Stone Tavern Farm, NY June 58 5.7 2.3 11.5 21.4 1.1 0 33
Apollo Rendezvous and Telescope Fair John Bryan State Park near Yellow Springs, OH June 29.5 16.7 14.4 20.5 18.9 0 0 44
Bryce Canyon Astronomy Festival Bryce Canyon National Park, UT June 77.2 5.2 4.7 7.4 5.4 0 0 14
Cherry Springs Star Party Cherry Springs State Park near Coudersport, PA June 44.7 7.6 5 10.8 29.7 2.2 0 44
Craters of the Moon Star Party - June Craters of the Moon National Monument, ID June  36.4 32.3 2.3 22.3 6.8 0 0 30
Golden State Star Party Frosty Acres Ranch, Adin, CA June 77.7 1.3 1.7 6.3 13 0 0 19
Grand Canyon Star Party South Rim, AZ June 88.4 3.2 2.3 3.5 2.6 0 0 7
Green Bank Star Quest Green Bank, WV June 39.9 7.9 4.9 13.8 29.9 3.6 0 48
Rocky Mountain Star Stare  Pike's National Forest, CO June 70.1 6.5 3.4 7.8 12.2 0 0 21
Sky Tour Monroeville, OH June 63.1 8 4.1 8.9 15.9 0 0 26
Starconn Middletown, CT June 50.7 7.1 5.2 7.6 28.4 0.9 0 39
Wisconsin Observers Weekend (WOW) Hartman Creek State Park, WI June 62.1 0 12.3 7.3 18.3 0 0 29
Connecticut River Valley Astronomers' Conjunction Northfield Mountain, MA  July 50.8 9.2 4.8 7.2 24.4 3.6 0 37
Indiana Family Star Party Camp Cullom near Frankfort, IN July 71.4 8.2 2.7 10.2 7.5 0 0 18
Mason-Dixon Star Party Shreveport Airport/Footlight Ranch, PA July 39.8 9.4 10.4 14.5 25 0.7 0.3 43
Montana Starwatch  Lewis & Clark National Forest, MT July 65.9 11.2 3.8 10.6 8.5 0 0 20
Mount Bachelor Star Party Mount Bachelor Ski Area, Bend, OR July 83.3 7.5 1.5 4.1 3.6 0 0 9
Nebraska Star Party Merritt Reservoir, NE July 72.6 7.2 3.1 4 12.8 0.2 0 19
Sola Fide Star Party Austin, MN July 60.5 4.7 8.5 7.8 17.9 0.6 0 29
Table Mountain Star Party Table Mountain, near Ellensberg, WA  July 85.5 4.6 1.7 5.9 2.4 0 0 8
Almost Heaven Star Party near Franklin, WV August 47.5 6.9 6.7 13.1 22.4 3.5 0 40
Deception Pass Star Party Deception Pass State Park, WA August 17.6 21.6 12.9 27.9 18.4 1.4 0.2 51
North Dakota Badlands Star Party North Unit, Theodore Roosevelt National Park, ND August 71.9 7.7 3.7 6.3 10.1 0.2 0 18
Shingletown Star Party Shingletown, CA August 88.3 5.6 2.4 2 1.6 0 0 5
Sierra Summer Star Party Alpine County Airport near Markleeville, CA August 95.4 1.3 1.1 1.6 0.5 0 0 2
Weekend Under the Stars  Foxpark, WY (west of Laramie) August 92.9 3.4 1.1 0.8 1.9 0 0 4
      Midnight Percent Frequency of...  
Name Location Date Clear Few Scattered Broken Overcast Obscured Partly obscured Average Cloud Amount
Iowa Star Party Coon Rapids, IA August 43 11.8 10.2 10 25 0 0 39
Northwoods Starfest Beaver Creek Reserve near Eau Claire, WI August 48.8 11.3 6.7 11.5 21.2 0.3 0 35
Oregon Star Party Ochoco National Forest, OR August 82.3 6.7 1.3 4.9 4.9 0 0 10
South Dakota Star Party near Beresford, SD August 64.8 7.5 3.3 10.2 13.6 0.3 0.3 24
Stellafane Breezy Hill, Springfield, VT August 47.5 4.8 3.7 13.8 26.3 4 0 43
Ark-La-Tex Star Party west of Nashville, AR September 62.1 3.4 3.4 10.3 17.2 3.4 0 31
Arunah Hill Days Arunah Hill near near Pittsfield, MA September 49.8 5.5 5.5 12.2 24.1 3 0 40
Astroblast Two Mile Run County Park, Franklin, PA September 46 11.6 1.9 16.3 21.9 2.3 0 40
Astrofest Kankakee, IL September 55.9 12.7 6.9 11.8 12.7 0 0 27
Big Meadows Star Gaze Shenandoa National Park, VA September 47.9 4.1 8.2 10.3 28.8 0.7 0 42
Black Forest Star Party Cherry Springs State Park, PA September 44.2 7.4 3 9.6 32.3 3.6 0 46
California Star Party (CalStar) Lake San Antonio, CA  September 39 3.6 1.9 6.4 42.8 6.4 0 56
Connecticut Star Party Ashford, CT September 48.4 5 5 7.4 31.3 2.9 0 43
Craters of the Moon Star Party - September Craters of the Moon National Monument, ID September 79.9 0 6.2 3.5 10.4 0 0 16
Delmarva No Frills Star Party Tukahoe State Park, MD September 75 0 5 5 15 0 0 21
Eagles Park Star Party (Fall)  near Montauk State Park, MO September 61.8 0 3.6 9.1 25.5 0 0 34
Great Lakes Star Gaze River Valley RV Park, Gladwin, MI September 45.9 0 8.8 6.8 36.6 2 0 48
Hidden Hollow Star Party Warren Rupp Observatory near Mansfield, OH September 66.9 6 2.7 5.7 18.2 0.5 0 25
Idaho Star Party Bruneau Dunes State Park, ID September 38.1 11.6 16.7 20.5 12.6 0.5 0 38
Illinois Dark Skies Star Party  Jim Edgar Panther Creek State Fish and Wildlife Area near Springfield, IL September 66 4.3 3.2 7 19.3 0.3 0 27
Okie-Tex Star Party Kenton, OK September 73.1 5.1 2.7 4.5 14.7 0 0 20
Prairie Skies Star Party Camp Shaw-Waw-Nas-See near Bourbonnais, IL September 55.9 12.7 6.9 11.8 12.7 0 0 27
Sola Fide Observatory Star Party Austin, MN September 60.3 4.5 5.1 5.8 24.3 0 0 32
South Jersey Fall Star Party Belle Plain State Forest, NJ  September 49.1 13.4 3.5 10.4 21.3 1.4 0.9 34
Tennessee Star Party Camp Nakanawa, Crossville, TN September 63.2 6.8 5.2 8 16.8 0 0 26
White Sands Star Party White Sands, NM September 85.2 0 7.9 3.7 3.2 0 0 10
      Midnight Percent Frequency of...  
Name Location Date Clear Few Scattered Broken Overcast Obscured Partly obscured Average Cloud Amount
All Arizona Star Party Farnsworth Ranch, south of Arizona City, AZ October 90.1 4.2 2.6 2.6 0.6 0 0 4
Blackwater Falls Astro Weekend  Blackwater Falls State Park, WV October 44.4 0 7.5 8.1 36.2 3.8 0 50
Central Texas Star Party Canyon of the Eagles Lodge, near Burnet, TX October 60.6 3.7 3.4 7.4 24.4 0.6 0 33
Eastern Iowa Star Party Wapsi River Environmental Education Center (WREEC), near Dixon, Iowa October 62 3.7 2.8 6.5 24.8 0.3 0 32
Eldorado Star Party northwest of Sonora, TX October 70.8 4.2 1.9 4.9 18.1 0.1 0 24
Enchanted Skies Star Party 30 miles S of Socorro, NM  October 91 1.1 0.8 1.9 5.3 0 0 7
Heart of America Star Party 15 mi SW Butler, MO October 60.9 4.8 4.3 6.1 23.9 0 0 31
ICStars Star Party IC Stars Ranch near Warrensburg, MO October 40.3 7.7 13.1 14.5 24.4 0 0 43
Jersey Starquest Hope, NJ  October 23.5 25.5 8.8 5.6 33.9 2.8 0 49
Mason-Dixon Star Party Shreveport Airport/Footlight Ranch, PA October 42.6 8.1 4.8 13.6 29.9 0.5 0.5 44
Mid-Atlantic Star Party (MASP) near Robbins, NC October 55.2 0 8 5.7 31 0 0 39
NOVAC Star Gaze Crockett Park south of Manassas, VI October 50.6 0 5.6 7.2 34.4 2.2 0 45
Peach State Star Gaze Deerlick Astronomy Village, Sharon, GA October 54.5 7.3 3.6 9.6 23.4 1.5 0 35
Starry Nights Festival Yucca Valley, CA October 63.4 19.2 6.8 9.1 1.6 0 0 15
Stella-Della-Valley Star Party  Camp Onas, near Ottsville, PA  October 47.6 7.7 4.8 8.5 30.5 0.8 0 41
Tennessee Fall Star Gaze Fall Creek Falls State Park near Spencer, TN October 57.1 6.8 1.7 7.2 24.9 2.2 0.2 35
Twin Lakes Star Party Pennyrile Forest State Park, KY October 62.5 4.6 1.6 6.8 24.1 0.5 0 31
Chiefland Astronomy Village Star Party Chiefland, FL  November 51.4 10.7 3.4 13.8 18.9 1.1 0.6 34
Deep South Regional Star Gaze Camp Ruth Lee, north of Baton Rouge, LA November 46.3 10.2 3.7 9.2 29.2 1.4 0 41
RTMC Nightfall Palm Canyon Resort, Borrego Springs, CA November 62.2 2.4 1.7 5.6 16.1 11.9 0 33