Haines Junction
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Haines Junction clear sky chart from 2005-11-06 to 2026-01-02.

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	6% 9% 4 11% 8% 7% 7% 6% 8% 9% 25%	131531
	Night	4 10% 5% 14% 9% 8% 7% 5% 7% 9% 21%	128413
Transparency	Day	50% 11% 16% 16% 6%	131181
	Night	54% 11% 14% 14% 6% 1	128341
Seeing	Day	12% 12% 26% 28% 16% 5%	18492
	Night	9% 7% 25% 34% 21% 4	24565

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 8% 5% 16% 11% 9% 8% 8% 8% 12% 15%	2246
	11th to 20th	Day	2 10% 6% 13% 12% 9% 7% 6% 8% 10% 16%	2259
	21st to end	Day	2 13% 7% 15% 9% 7% 6% 5% 7% 10% 20%	3158
February	1st to 10th	Day	2 10% 4 17% 10% 8% 7% 5% 9% 8% 20%	1400
	11th to 20th	Day	2 12% 6% 17% 10% 8% 6% 4 7% 10% 19%	1541
	21st to end	Day	1 9% 6% 14% 10% 7% 9% 6% 8% 8% 21%	1485
March	1st to 10th	Day	6% 5% 15% 12% 12% 9% 6% 7% 8% 20%	4270
	11th to 20th	Day	1 8% 5% 16% 10% 9% 9% 5% 8% 9% 21%	4883
	21st to end	Day	1 7% 4 14% 9% 9% 9% 6% 9% 10% 22%	5775
April	1st to 10th	Day	1 9% 6% 14% 8% 7% 7% 6% 9% 10% 23%	2497
	11th to 20th	Day	2 12% 4 12% 8% 6% 6% 6% 7% 9% 29%	2707
	21st to end	Day	3 10% 5% 10% 8% 7% 6% 6% 8% 11% 26%	2825
May	1st to 10th	Day	3 12% 4 10% 8% 7% 7% 6% 8% 10% 25%	7081
	11th to 20th	Day	4 10% 4 11% 8% 7% 7% 6% 8% 9% 27%	7193
	21st to end	Day	4 8% 3 8% 6% 6% 7% 6% 9% 10% 32%	8282
June	1st to 10th	Day	9% 7% 3 8% 6% 6% 6% 6% 8% 9% 33%	3600
	11th to 20th	Day	12% 9% 4 8% 6% 6% 6% 5% 7% 9% 27%	3600
	21st to end	Day	8% 6% 3 7% 7% 6% 6% 6% 8% 8% 34%	3600
July	1st to 10th	Day	9% 8% 3 8% 6% 6% 7% 5% 8% 9% 30%	7983
	11th to 20th	Day	10% 8% 3 9% 6% 7% 7% 6% 8% 9% 26%	7700
	21st to end	Day	13% 8% 3 7% 5% 6% 6% 5% 7% 10% 31%	8023
August	1st to 10th	Day	7% 6% 2 6% 4 4 5% 5% 7% 8% 46%	4984
	11th to 20th	Day	10% 8% 3 7% 5% 5% 6% 4 7% 10% 34%	4649
	21st to end	Day	13% 10% 3 9% 6% 7% 7% 6% 8% 10% 22%	4918
September	1st to 10th	Day	14% 11% 4 10% 7% 5% 6% 4 6% 7% 25%	2491
	11th to 20th	Day	9% 11% 4 11% 6% 7% 6% 6% 8% 7% 25%	2400
	21st to end	Day	10% 14% 4 10% 7% 6% 7% 6% 7% 9% 20%	2111
October	1st to 10th	Day	7% 13% 5% 11% 7% 8% 8% 7% 8% 9% 17%	3270
	11th to 20th	Day	6% 11% 6% 15% 7% 6% 6% 6% 8% 10% 19%	2885
	21st to end	Day	4 15% 7% 16% 8% 8% 7% 6% 7% 8% 13%	2842
November	1st to 10th	Day	5% 16% 6% 22% 11% 8% 6% 3 6% 5% 12%	1442
	11th to 20th	Day	2 17% 9% 18% 11% 8% 8% 5% 6% 7% 8%	1260
	21st to end	Day	2 11% 7% 21% 11% 9% 7% 6% 7% 8% 10%	1249
December	1st to 10th	Day	2 11% 6% 14% 9% 8% 9% 5% 10% 9% 16%	1356
	11th to 20th	Day	1 7% 4 18% 16% 12% 11% 5% 7% 9% 12%	1542
	21st to end	Day	1 13% 7% 18% 15% 10% 10% 5% 7% 6% 7%	2024
January	1st to 10th	Night	1 11% 6% 17% 11% 8% 8% 8% 8% 9% 13%	7751
	11th to 20th	Night	2 10% 5% 13% 10% 7% 7% 5% 8% 16% 18%	7638
	21st to end	Night	2 12% 6% 14% 10% 8% 6% 5% 7% 10% 19%	7805
February	1st to 10th	Night	2 11% 6% 15% 12% 10% 7% 5% 8% 7% 18%	3000
	11th to 20th	Night	2 11% 7% 17% 8% 6% 7% 5% 7% 9% 20%	2742
	21st to end	Night	2 10% 6% 14% 11% 6% 6% 5% 8% 10% 22%	2145
March	1st to 10th	Night	7% 4 15% 13% 10% 11% 7% 7% 8% 18%	5604
	11th to 20th	Night	1 9% 5% 16% 9% 9% 10% 7% 8% 8% 18%	5076
	21st to end	Night	1 9% 6% 17% 8% 7% 7% 6% 7% 9% 24%	5169
April	1st to 10th	Night	1 6% 4 12% 7% 8% 6% 5% 8% 10% 31%	1900
	11th to 20th	Night	1 10% 4 12% 7% 7% 7% 5% 8% 10% 28%	1641
	21st to end	Night	2 7% 4 9% 7% 6% 8% 6% 10% 10% 33%	1574
May	1st to 10th	Night	1 5% 3 9% 6% 7% 8% 7% 9% 10% 33%	2872
	11th to 20th	Night	3 7% 3 11% 7% 6% 6% 5% 8% 10% 35%	2702
	21st to end	Night	3 8% 3 8% 5% 6% 6% 5% 7% 12% 37%	2576
June	1st to 10th	Night	9% 6% 3 6% 6% 6% 6% 6% 8% 11% 34%	800
	11th to 20th	Night	13% 10% 3 8% 5% 5% 5% 6% 8% 8% 29%	800
	21st to end	Night	6% 6% 3 7% 6% 7% 7% 6% 8% 10% 35%	800
July	1st to 10th	Night	6% 7% 3 7% 5% 4 6% 4 6% 10% 42%	1974
	11th to 20th	Night	8% 8% 3 7% 6% 8% 8% 5% 7% 10% 30%	2260
	21st to end	Night	14% 7% 2 8% 5% 6% 5% 5% 8% 9% 31%	2820
August	1st to 10th	Night	6% 4 2 5% 4 5% 5% 5% 7% 8% 49%	2170
	11th to 20th	Night	13% 5% 3 5% 3 4 5% 4 7% 10% 43%	2409
	21st to end	Night	8% 8% 3 8% 8% 7% 6% 6% 7% 9% 30%	2978
September	1st to 10th	Night	13% 9% 2 9% 6% 6% 6% 6% 8% 9% 27%	1909
	11th to 20th	Night	7% 10% 3 9% 6% 5% 7% 5% 7% 9% 32%	2000
	21st to end	Night	8% 15% 4 10% 7% 5% 5% 5% 7% 8% 26%	2288
October	1st to 10th	Night	7% 14% 4 11% 6% 6% 7% 5% 8% 10% 22%	3920
	11th to 20th	Night	6% 14% 7% 17% 6% 6% 5% 4 5% 6% 25%	4262
	21st to end	Night	4 17% 8% 17% 8% 7% 6% 4 5% 6% 19%	4959
November	1st to 10th	Night	4 15% 6% 19% 11% 8% 7% 5% 5% 6% 14%	3074
	11th to 20th	Night	3 16% 8% 21% 11% 8% 7% 4 5% 7% 10%	3360
	21st to end	Night	3 13% 5% 18% 13% 9% 9% 6% 7% 7% 10%	3360
December	1st to 10th	Night	3 12% 7% 17% 9% 8% 7% 5% 8% 9% 15%	6031
	11th to 20th	Night	1 8% 5% 17% 13% 10% 9% 7% 8% 9% 12%	6870
	21st to end	Night	3 14% 7% 19% 12% 10% 8% 5% 6% 7% 9%	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	54% 11% 15% 7% 12% 1	2246
	11th to 20th	Day	56% 10% 12% 12% 9% 1	2274
	21st to end	Day	55% 10% 13% 10% 8% 3	3158
February	1st to 10th	Day	57% 9% 10% 13% 10% 2	1400
	11th to 20th	Day	59% 10% 11% 10% 11%	1549
	21st to end	Day	54% 10% 13% 16% 7%	1485
March	1st to 10th	Day	53% 10% 14% 14% 9% 1	4270
	11th to 20th	Day	51% 12% 12% 11% 11% 2	4883
	21st to end	Day	47% 15% 19% 13% 5% 1	5775
April	1st to 10th	Day	53% 12% 17% 14% 4	2497
	11th to 20th	Day	50% 12% 12% 19% 7% 1	2707
	21st to end	Day	49% 13% 17% 16% 5%	2825
May	1st to 10th	Day	48% 11% 13% 20% 8%	7081
	11th to 20th	Day	46% 11% 17% 19% 7%	7196
	21st to end	Day	42% 9% 15% 22% 12%	8283
June	1st to 10th	Day	45% 12% 15% 20% 7% 1	3600
	11th to 20th	Day	50% 14% 16% 18% 3	3600
	21st to end	Day	44% 12% 17% 23% 4	3600
July	1st to 10th	Day	45% 11% 21% 19% 4	7897
	11th to 20th	Day	48% 10% 20% 19% 2	7607
	21st to end	Day	45% 11% 25% 16% 3	7798
August	1st to 10th	Day	34% 9% 23% 22% 10% 1	4965
	11th to 20th	Day	43% 12% 20% 21% 5%	4694
	21st to end	Day	52% 11% 21% 15% 1	4917
September	1st to 10th	Day	57% 11% 15% 16% 2	2491
	11th to 20th	Day	53% 13% 13% 18% 3	2400
	21st to end	Day	56% 12% 14% 15% 3	2111
October	1st to 10th	Day	57% 12% 13% 15% 3	3270
	11th to 20th	Day	55% 11% 18% 14% 2	2885
	21st to end	Day	62% 13% 13% 9% 3	2842
November	1st to 10th	Day	71% 8% 8% 9% 3	1442
	11th to 20th	Day	72% 10% 7% 8% 3	1260
	21st to end	Day	67% 11% 9% 7% 5%	1249
December	1st to 10th	Day	57% 15% 17% 7% 4	1356
	11th to 20th	Day	65% 9% 10% 9% 7% 1	1544
	21st to end	Day	66% 14% 10% 5% 4	2024
January	1st to 10th	Night	60% 11% 9% 9% 10% 1	7751
	11th to 20th	Night	51% 10% 13% 15% 8% 3	7685
	21st to end	Night	56% 11% 13% 10% 6% 3	7805
February	1st to 10th	Night	60% 10% 9% 12% 8% 2	3000
	11th to 20th	Night	57% 10% 11% 12% 8% 1	2745
	21st to end	Night	53% 10% 13% 14% 8% 1	2145
March	1st to 10th	Night	54% 9% 13% 13% 10%	5604
	11th to 20th	Night	52% 14% 13% 13% 8%	5078
	21st to end	Night	50% 14% 14% 16% 7%	5169
April	1st to 10th	Night	44% 12% 18% 19% 6%	1900
	11th to 20th	Night	47% 11% 15% 19% 8%	1641
	21st to end	Night	40% 13% 19% 21% 6%	1574
May	1st to 10th	Night	40% 11% 13% 24% 12% 1	2869
	11th to 20th	Night	38% 12% 16% 24% 9%	2702
	21st to end	Night	36% 8% 16% 33% 8%	2576
June	1st to 10th	Night	41% 11% 23% 20% 6%	800
	11th to 20th	Night	50% 14% 20% 15% 1	800
	21st to end	Night	41% 14% 18% 25% 2	800
July	1st to 10th	Night	36% 11% 30% 20% 3	1951
	11th to 20th	Night	44% 12% 23% 20% 1	2230
	21st to end	Night	46% 11% 27% 16% 1	2740
August	1st to 10th	Night	30% 13% 25% 24% 7% 2	2164
	11th to 20th	Night	37% 11% 21% 25% 6%	2430
	21st to end	Night	45% 14% 21% 20% 1	2978
September	1st to 10th	Night	51% 16% 18% 15% 2	1909
	11th to 20th	Night	46% 13% 19% 19% 2	2000
	21st to end	Night	53% 13% 14% 16% 3	2288
October	1st to 10th	Night	53% 11% 15% 19% 2	3920
	11th to 20th	Night	58% 9% 10% 20% 3	4262
	21st to end	Night	64% 11% 11% 10% 4	4959
November	1st to 10th	Night	67% 11% 9% 10% 3	3074
	11th to 20th	Night	72% 9% 7% 8% 4	3360
	21st to end	Night	67% 11% 10% 9% 4	3360
December	1st to 10th	Night	60% 12% 14% 12% 2	6031
	11th to 20th	Night	62% 11% 9% 11% 6%	6867
	21st to end	Night	66% 11% 10% 6% 5% 1	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	4 3 17% 35% 29% 13%	101
	11th to 20th	Day	2 7% 15% 42% 20% 15%	101
	21st to end	Day	8% 10% 29% 28% 16% 9%	295
February	1st to 10th	Day	8% 7% 20% 35% 22% 8%	400
	11th to 20th	Day	5% 8% 25% 36% 14% 12%	395
	21st to end	Day	6% 6% 30% 33% 18% 7%	331
March	1st to 10th	Day	5% 9% 28% 29% 19% 11%	400
	11th to 20th	Day	7% 11% 29% 29% 19% 7%	400
	21st to end	Day	5% 12% 28% 28% 19% 9%	506
April	1st to 10th	Day	5% 13% 31% 32% 16% 3	597
	11th to 20th	Day	10% 14% 25% 29% 19% 4	690
	21st to end	Day	8% 13% 26% 31% 17% 4	700
May	1st to 10th	Day	12% 21% 32% 23% 10% 2	703
	11th to 20th	Day	12% 16% 29% 25% 13% 5%	725
	21st to end	Day	11% 14% 35% 25% 11% 3	795
June	1st to 10th	Day	12% 11% 28% 28% 17% 4	930
	11th to 20th	Day	16% 10% 25% 28% 18% 3	930
	21st to end	Day	10% 9% 24% 29% 22% 5%	930
July	1st to 10th	Day	12% 8% 25% 30% 21% 4	846
	11th to 20th	Day	14% 14% 26% 25% 17% 4	718
	21st to end	Day	16% 10% 26% 25% 18% 5%	794
August	1st to 10th	Day	13% 11% 27% 29% 15% 5%	726
	11th to 20th	Day	17% 20% 28% 20% 11% 4	715
	21st to end	Day	19% 14% 28% 25% 11% 4	803
September	1st to 10th	Day	21% 17% 24% 20% 14% 5%	621
	11th to 20th	Day	14% 15% 25% 23% 18% 5%	530
	21st to end	Day	20% 18% 25% 19% 11% 6%	438
October	1st to 10th	Day	20% 21% 21% 20% 12% 6%	420
	11th to 20th	Day	15% 14% 28% 26% 13% 5%	420
	21st to end	Day	10% 8% 23% 32% 20% 6%	462
November	1st to 10th	Day	9% 9% 28% 33% 17% 4	281
	11th to 20th	Day	11% 8% 18% 35% 18% 10%	220
	21st to end	Day	5% 9% 21% 36% 20% 9%	220
December	1st to 10th	Day	4 8% 22% 37% 17% 11%	118
	11th to 20th	Day	4 9% 12% 39% 25% 12%	110
	21st to end	Day	4 11% 14% 35% 22% 14%	121
January	1st to 10th	Night	6% 3 24% 41% 21% 6%	927
	11th to 20th	Night	6% 7% 28% 38% 17% 5%	900
	21st to end	Night	8% 11% 30% 31% 17% 4	990
February	1st to 10th	Night	7% 6% 23% 44% 18% 3	900
	11th to 20th	Night	4 8% 32% 33% 19% 4	884
	21st to end	Night	7% 7% 28% 40% 15% 4	743
March	1st to 10th	Night	5% 7% 28% 34% 22% 4	850
	11th to 20th	Night	5% 8% 26% 33% 25% 4	646
	21st to end	Night	5% 7% 24% 35% 25% 4	660
April	1st to 10th	Night	3 6% 26% 35% 27% 4	600
	11th to 20th	Night	6% 4 24% 31% 30% 4	593
	21st to end	Night	5% 5% 20% 35% 32% 4	600
May	1st to 10th	Night	8% 10% 22% 31% 27% 2	474
	11th to 20th	Night	9% 8% 24% 34% 24% 1	394
	21st to end	Night	7% 5% 23% 36% 28% 1	281
June	1st to 10th	Night	11% 1 22% 40% 26%	200
	11th to 20th	Night	16% 6% 19% 40% 20%	200
	21st to end	Night	8% 4 22% 40% 27% 1	200
July	1st to 10th	Night	8% 4 22% 38% 28%	195
	11th to 20th	Night	13% 4 18% 39% 25%	194
	21st to end	Night	14% 7% 21% 33% 25% 1	369
August	1st to 10th	Night	9% 6% 27% 37% 19% 1	524
	11th to 20th	Night	18% 8% 26% 27% 20% 2	594
	21st to end	Night	17% 6% 22% 34% 20% 1	660
September	1st to 10th	Night	18% 10% 25% 27% 18% 2	600
	11th to 20th	Night	14% 8% 23% 31% 21% 3	600
	21st to end	Night	17% 11% 25% 27% 17% 4	723
October	1st to 10th	Night	17% 12% 27% 27% 15% 2	800
	11th to 20th	Night	16% 9% 26% 32% 16% 2	847
	21st to end	Night	10% 6% 30% 33% 19% 3	1001
November	1st to 10th	Night	11% 5% 27% 38% 16% 3	930
	11th to 20th	Night	10% 7% 22% 35% 20% 5%	950
	21st to end	Night	8% 9% 25% 34% 20% 4	950
December	1st to 10th	Night	8% 7% 26% 34% 21% 4	1150
	11th to 20th	Night	9% 6% 21% 35% 22% 8%	1160
	21st to end	Night	9% 6% 22% 36% 21% 6%	1276

Page generated at 2025-12-29 22:14:10. Version ac07

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