Carmacks
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Carmacks clear sky chart from 2005-11-06 to 2026-08-15.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	7% 9% 4 11% 8% 7% 7% 5% 7% 9% 25%	150059
	Night	5% 10% 5% 13% 9% 8% 7% 6% 8% 8% 21%	140467
Transparency	Day	53% 2 16% 21% 7%	149695
	Night	56% 3 13% 19% 7% 1	140415
Seeing	Day	14% 7% 21% 29% 21% 8%	19590
	Night	11% 6% 17% 33% 27% 7%	25359

By Month

Percentage Cloud Cover NW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	1 9% 5% 18% 10% 11% 10% 5% 9% 10% 12%	2347
	11th to 20th	Day	2 9% 4 13% 11% 9% 9% 6% 9% 12% 16%	2925
	21st to end	Day	1 9% 6% 15% 9% 8% 8% 6% 8% 9% 22%	3727
February	1st to 10th	Day	2 10% 6% 14% 9% 9% 9% 6% 8% 9% 18%	1446
	11th to 20th	Day	3 11% 5% 14% 10% 9% 7% 5% 8% 9% 18%	1573
	21st to end	Day	1 10% 6% 13% 10% 9% 8% 7% 7% 8% 21%	1529
March	1st to 10th	Day	1 8% 4 19% 12% 8% 7% 5% 6% 7% 25%	4407
	11th to 20th	Day	2 12% 5% 16% 10% 8% 7% 5% 7% 7% 21%	4897
	21st to end	Day	1 6% 5% 14% 7% 7% 6% 5% 8% 9% 32%	5993
April	1st to 10th	Day	3 12% 5% 13% 7% 6% 7% 6% 6% 9% 27%	2604
	11th to 20th	Day	4 12% 4 11% 7% 6% 7% 5% 6% 8% 29%	2904
	21st to end	Day	4 11% 4 11% 8% 7% 7% 5% 7% 7% 29%	2998
May	1st to 10th	Day	4 9% 3 10% 7% 7% 6% 5% 7% 9% 32%	9391
	11th to 20th	Day	4 8% 4 11% 8% 7% 8% 6% 8% 9% 27%	9352
	21st to end	Day	6% 9% 4 9% 6% 7% 7% 5% 9% 10% 29%	11547
June	1st to 10th	Day	8% 9% 4 11% 8% 7% 8% 5% 7% 7% 26%	3780
	11th to 20th	Day	9% 10% 5% 11% 8% 7% 6% 5% 7% 9% 23%	3780
	21st to end	Day	11% 8% 3 9% 8% 7% 8% 6% 8% 9% 22%	3780
July	1st to 10th	Day	13% 10% 4 10% 7% 8% 7% 6% 8% 8% 20%	10620
	11th to 20th	Day	9% 8% 3 9% 6% 6% 7% 5% 8% 11% 29%	10387
	21st to end	Day	12% 7% 3 9% 7% 6% 7% 5% 8% 10% 25%	10575
August	1st to 10th	Day	8% 6% 3 8% 5% 5% 6% 5% 6% 8% 39%	5308
	11th to 20th	Day	15% 9% 3 9% 6% 6% 6% 5% 7% 9% 27%	4735
	21st to end	Day	13% 10% 4 9% 7% 7% 7% 5% 7% 9% 21%	5027
September	1st to 10th	Day	12% 11% 3 10% 7% 6% 6% 5% 6% 9% 25%	2489
	11th to 20th	Day	9% 8% 3 9% 7% 7% 6% 5% 7% 8% 31%	2400
	21st to end	Day	13% 10% 4 9% 6% 7% 6% 5% 7% 8% 27%	2118
October	1st to 10th	Day	7% 10% 3 9% 6% 7% 6% 5% 9% 9% 29%	3270
	11th to 20th	Day	6% 11% 4 10% 6% 6% 7% 5% 6% 8% 30%	2819
	21st to end	Day	7% 17% 8% 15% 9% 7% 6% 4 6% 6% 16%	2810
November	1st to 10th	Day	4 16% 8% 14% 8% 7% 8% 5% 6% 6% 17%	1358
	11th to 20th	Day	4 17% 8% 15% 10% 8% 7% 5% 6% 5% 12%	1260
	21st to end	Day	4 13% 6% 15% 10% 8% 8% 10% 8% 6% 14%	997
December	1st to 10th	Day	4 11% 6% 16% 8% 7% 6% 6% 10% 10% 17%	1340
	11th to 20th	Day	2 9% 5% 18% 11% 8% 9% 8% 10% 9% 11%	1542
	21st to end	Day	2 11% 6% 16% 11% 9% 7% 5% 8% 9% 14%	2024
January	1st to 10th	Night	2 8% 5% 16% 13% 12% 10% 7% 8% 8% 11%	10562
	11th to 20th	Night	3 10% 5% 11% 8% 7% 8% 6% 10% 11% 21%	10015
	21st to end	Night	3 11% 4 15% 10% 10% 9% 7% 7% 8% 17%	10452
February	1st to 10th	Night	2 10% 6% 15% 11% 8% 7% 5% 7% 9% 20%	3171
	11th to 20th	Night	1 10% 4 14% 9% 8% 6% 6% 8% 9% 24%	2934
	21st to end	Night	1 9% 5% 12% 8% 8% 8% 5% 7% 8% 29%	2275
March	1st to 10th	Night	1 6% 3 15% 10% 8% 6% 6% 8% 9% 27%	5687
	11th to 20th	Night	2 13% 6% 14% 10% 7% 7% 5% 7% 7% 22%	5287
	21st to end	Night	1 8% 5% 13% 7% 8% 7% 5% 8% 8% 29%	5198
April	1st to 10th	Night	2 10% 4 12% 8% 5% 5% 5% 7% 9% 33%	2013
	11th to 20th	Night	3 9% 4 12% 8% 7% 7% 6% 8% 7% 30%	1665
	21st to end	Night	4 8% 4 9% 6% 6% 6% 6% 8% 9% 33%	1620
May	1st to 10th	Night	3 6% 3 9% 7% 7% 8% 7% 10% 10% 30%	3528
	11th to 20th	Night	5% 8% 3 8% 6% 6% 7% 5% 8% 9% 34%	3510
	21st to end	Night	4 6% 2 7% 6% 7% 7% 6% 9% 10% 36%	2622
June	1st to 10th	Night	8% 9% 3 7% 6% 7% 8% 5% 10% 9% 29%	840
	11th to 20th	Night	8% 8% 3 11% 8% 7% 8% 7% 9% 8% 24%	840
	21st to end	Night	11% 8% 4 10% 7% 7% 9% 7% 11% 8% 20%	840
July	1st to 10th	Night	12% 13% 3 11% 7% 6% 6% 5% 6% 8% 22%	2340
	11th to 20th	Night	9% 7% 3 8% 5% 7% 6% 6% 9% 10% 30%	2571
	21st to end	Night	13% 10% 3 8% 5% 6% 6% 7% 9% 11% 23%	3492
August	1st to 10th	Night	6% 5% 3 8% 5% 5% 6% 5% 8% 8% 41%	2063
	11th to 20th	Night	15% 9% 3 6% 5% 4 6% 6% 7% 9% 29%	2412
	21st to end	Night	10% 9% 5% 11% 7% 7% 7% 5% 8% 8% 22%	2882
September	1st to 10th	Night	10% 9% 3 11% 7% 7% 7% 5% 7% 9% 25%	1910
	11th to 20th	Night	7% 6% 3 9% 7% 8% 7% 6% 6% 9% 32%	2000
	21st to end	Night	10% 11% 4 10% 6% 7% 7% 4 7% 7% 25%	2279
October	1st to 10th	Night	7% 9% 4 9% 6% 6% 5% 5% 8% 10% 30%	3920
	11th to 20th	Night	7% 13% 4 10% 7% 6% 5% 5% 7% 8% 28%	4326
	21st to end	Night	6% 18% 6% 16% 9% 6% 6% 4 6% 7% 15%	4990
November	1st to 10th	Night	6% 14% 6% 16% 8% 7% 7% 5% 6% 7% 18%	3159
	11th to 20th	Night	3 17% 8% 20% 11% 8% 7% 4 5% 5% 12%	3360
	21st to end	Night	5% 15% 6% 16% 11% 9% 8% 8% 7% 5% 12%	3600
December	1st to 10th	Night	5% 15% 6% 14% 9% 7% 7% 6% 8% 9% 14%	6060
	11th to 20th	Night	2 10% 6% 18% 11% 8% 9% 6% 9% 9% 11%	6870
	21st to end	Night	4 13% 7% 16% 12% 8% 8% 5% 7% 7% 13%	9174

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	64% 3 6% 14% 11% 2	2347
	11th to 20th	Day	54% 4 15% 15% 11%	2940
	21st to end	Day	54% 4 13% 19% 8% 3	3728
February	1st to 10th	Day	56% 4 10% 18% 11% 1	1446
	11th to 20th	Day	59% 4 12% 14% 10%	1580
	21st to end	Day	57% 4 14% 17% 8%	1529
March	1st to 10th	Day	59% 1 8% 25% 6%	4407
	11th to 20th	Day	59% 3 10% 17% 11%	4897
	21st to end	Day	45% 2 18% 22% 11% 1	5993
April	1st to 10th	Day	52% 4 16% 22% 6%	2604
	11th to 20th	Day	50% 3 14% 23% 10%	2904
	21st to end	Day	49% 3 15% 24% 9%	2998
May	1st to 10th	Day	46% 2 15% 25% 12%	9391
	11th to 20th	Day	50% 1 9% 28% 11%	9355
	21st to end	Day	47% 2 7% 24% 19% 1	11548
June	1st to 10th	Day	55% 2 11% 24% 8%	3780
	11th to 20th	Day	57% 2 13% 22% 5%	3780
	21st to end	Day	55% 3 18% 21% 3	3780
July	1st to 10th	Day	59% 2 16% 19% 5%	10531
	11th to 20th	Day	47% 2 29% 19% 3	10288
	21st to end	Day	52% 2 25% 19% 2	10345
August	1st to 10th	Day	43% 3 22% 21% 10% 1	5289
	11th to 20th	Day	53% 3 19% 21% 3	4780
	21st to end	Day	56% 2 23% 17% 1	5026
September	1st to 10th	Day	55% 3 20% 18% 3	2489
	11th to 20th	Day	49% 3 23% 23% 2	2400
	21st to end	Day	54% 3 19% 21% 3	2118
October	1st to 10th	Day	49% 4 20% 23% 4	3270
	11th to 20th	Day	49% 3 18% 27% 3	2819
	21st to end	Day	67% 4 14% 13% 2	2810
November	1st to 10th	Day	62% 5% 14% 17% 3	1358
	11th to 20th	Day	69% 3 13% 11% 3	1260
	21st to end	Day	62% 5% 13% 15% 5%	997
December	1st to 10th	Day	56% 8% 21% 10% 4	1340
	11th to 20th	Day	65% 3 7% 13% 12%	1544
	21st to end	Day	63% 4 11% 17% 5%	2024
January	1st to 10th	Night	66% 4 6% 12% 11%	10563
	11th to 20th	Night	51% 4 13% 20% 9% 3	10062
	21st to end	Night	60% 4 10% 18% 6% 2	10452
February	1st to 10th	Night	57% 5% 8% 18% 11% 1	3171
	11th to 20th	Night	53% 4 11% 21% 10% 1	2938
	21st to end	Night	50% 4 15% 20% 12%	2275
March	1st to 10th	Night	51% 1 10% 28% 10%	5687
	11th to 20th	Night	58% 2 7% 22% 10% 1	5289
	21st to end	Night	48% 3 14% 22% 12% 1	5198
April	1st to 10th	Night	46% 3 18% 23% 8% 1	2013
	11th to 20th	Night	48% 3 13% 26% 9% 1	1665
	21st to end	Night	44% 3 17% 27% 9%	1620
May	1st to 10th	Night	44% 2 15% 30% 9% 1	3525
	11th to 20th	Night	44% 1 12% 30% 13%	3510
	21st to end	Night	38% 2 7% 30% 23% 1	2626
June	1st to 10th	Night	46% 3 13% 29% 8% 1	840
	11th to 20th	Night	52% 5% 13% 24% 5%	840
	21st to end	Night	55% 4 16% 21% 4	840
July	1st to 10th	Night	58% 2 16% 20% 3	2320
	11th to 20th	Night	46% 2 30% 20% 3	2547
	21st to end	Night	51% 2 27% 17% 2	3417
August	1st to 10th	Night	37% 3 25% 22% 12% 1	2057
	11th to 20th	Night	49% 3 20% 26% 2	2433
	21st to end	Night	56% 2 18% 23% 1	2882
September	1st to 10th	Night	56% 3 19% 19% 2	1910
	11th to 20th	Night	46% 3 23% 24% 4	2000
	21st to end	Night	55% 3 16% 21% 5%	2279
October	1st to 10th	Night	48% 3 17% 28% 3	3920
	11th to 20th	Night	52% 2 14% 27% 3	4326
	21st to end	Night	66% 5% 16% 12% 2	4990
November	1st to 10th	Night	63% 4 16% 15% 3	3159
	11th to 20th	Night	72% 3 10% 12% 3	3360
	21st to end	Night	66% 4 11% 15% 3	3600
December	1st to 10th	Night	62% 5% 17% 13% 3	6060
	11th to 20th	Night	64% 5% 11% 12% 6% 1	6867
	21st to end	Night	66% 4 10% 12% 6% 2	9174

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	5% 4 13% 29% 40% 10%	110
	11th to 20th	Day	11% 1 14% 36% 19% 19%	110
	21st to end	Day	9% 6% 19% 33% 22% 12%	215
February	1st to 10th	Day	7% 3 17% 38% 24% 10%	406
	11th to 20th	Day	8% 5% 18% 35% 21% 13%	425
	21st to end	Day	6% 8% 23% 37% 21% 5%	355
March	1st to 10th	Day	6% 8% 23% 29% 23% 12%	430
	11th to 20th	Day	6% 9% 26% 30% 20% 10%	430
	21st to end	Day	6% 7% 25% 29% 21% 13%	566
April	1st to 10th	Day	12% 10% 25% 29% 19% 7%	624
	11th to 20th	Day	12% 11% 24% 28% 20% 5%	740
	21st to end	Day	11% 10% 23% 32% 17% 8%	750
May	1st to 10th	Day	18% 15% 28% 25% 11% 4	753
	11th to 20th	Day	13% 10% 27% 27% 16% 6%	775
	21st to end	Day	14% 9% 27% 27% 18% 4	1045
June	1st to 10th	Day	15% 7% 18% 31% 23% 6%	990
	11th to 20th	Day	16% 6% 17% 31% 23% 8%	990
	21st to end	Day	15% 4 16% 28% 25% 11%	990
July	1st to 10th	Day	14% 5% 19% 29% 26% 8%	976
	11th to 20th	Day	17% 5% 19% 28% 22% 9%	895
	21st to end	Day	18% 3 15% 29% 26% 9%	849
August	1st to 10th	Day	13% 4 23% 29% 21% 10%	776
	11th to 20th	Day	21% 7% 23% 25% 16% 7%	736
	21st to end	Day	17% 6% 22% 32% 19% 4	803
September	1st to 10th	Day	20% 10% 20% 20% 21% 8%	610
	11th to 20th	Day	17% 8% 21% 25% 20% 8%	530
	21st to end	Day	22% 12% 23% 22% 15% 7%	458
October	1st to 10th	Day	19% 11% 29% 20% 15% 7%	420
	11th to 20th	Day	20% 11% 21% 22% 18% 7%	420
	21st to end	Day	16% 6% 16% 28% 24% 9%	442
November	1st to 10th	Day	17% 5% 21% 27% 22% 7%	220
	11th to 20th	Day	10% 5% 12% 37% 26% 10%	220
	21st to end	Day	9% 5% 14% 32% 24% 16%	190
December	1st to 10th	Day	7% 5% 16% 32% 28% 12%	110
	11th to 20th	Day	13% 1 15% 31% 26% 14%	110
	21st to end	Day	6% 6% 17% 26% 30% 17%	121
January	1st to 10th	Night	6% 5% 13% 35% 33% 9%	1160
	11th to 20th	Night	11% 5% 15% 41% 24% 4	966
	21st to end	Night	10% 4 21% 37% 21% 6%	1045
February	1st to 10th	Night	6% 4 15% 41% 28% 6%	950
	11th to 20th	Night	5% 7% 18% 40% 24% 6%	934
	21st to end	Night	6% 5% 20% 43% 22% 4	783
March	1st to 10th	Night	6% 7% 20% 34% 28% 6%	886
	11th to 20th	Night	5% 6% 22% 33% 26% 8%	725
	21st to end	Night	6% 5% 19% 30% 30% 9%	693
April	1st to 10th	Night	8% 5% 20% 33% 28% 7%	630
	11th to 20th	Night	7% 5% 19% 34% 28% 6%	623
	21st to end	Night	8% 7% 16% 30% 34% 6%	614
May	1st to 10th	Night	13% 12% 18% 27% 26% 4	420
	11th to 20th	Night	12% 9% 23% 30% 25% 1	414
	21st to end	Night	8% 6% 26% 28% 29% 3	231
June	1st to 10th	Night	13% 8% 18% 28% 27% 6%	210
	11th to 20th	Night	14% 6% 13% 29% 36% 3	210
	21st to end	Night	14% 7% 15% 24% 32% 8%	210
July	1st to 10th	Night	15% 2 16% 29% 37% 2	205
	11th to 20th	Night	17% 3 16% 24% 32% 8%	204
	21st to end	Night	17% 4 12% 25% 35% 6%	332
August	1st to 10th	Night	11% 5% 17% 31% 31% 5%	442
	11th to 20th	Night	19% 6% 16% 25% 26% 7%	606
	21st to end	Night	15% 4 15% 29% 31% 6%	660
September	1st to 10th	Night	17% 9% 15% 26% 25% 8%	600
	11th to 20th	Night	12% 8% 18% 33% 25% 5%	600
	21st to end	Night	18% 9% 16% 27% 22% 7%	754
October	1st to 10th	Night	20% 10% 18% 28% 20% 5%	800
	11th to 20th	Night	20% 7% 13% 30% 25% 5%	842
	21st to end	Night	14% 5% 14% 35% 24% 7%	1001
November	1st to 10th	Night	14% 5% 14% 37% 23% 6%	930
	11th to 20th	Night	10% 3 17% 34% 29% 8%	950
	21st to end	Night	13% 5% 18% 30% 26% 9%	1133
December	1st to 10th	Night	12% 4 16% 37% 25% 7%	1160
	11th to 20th	Night	12% 3 15% 36% 27% 7%	1160
	21st to end	Night	9% 4 12% 36% 27% 11%	1276

Page generated at 2026-08-11 23:37:14. Version ac07

Copyright © 2026 Attilla Danko.