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 2024-11-12.

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% 10% 4 12% 8% 7% 7% 5% 7% 9% 25%	106359
	Night	4 12% 6% 14% 9% 7% 7% 5% 7% 8% 21%	101344
Transparency	Day	52% 11% 16% 16% 5%	106057
	Night	57% 11% 13% 14% 5% 1	101293
Seeing	Day	12% 13% 26% 27% 16% 5%	17092
	Night	10% 7% 25% 34% 21% 4	22995

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	2 10% 6% 18% 14% 12% 10% 8% 6% 7% 7%	1561
	11th to 20th	Day	2 14% 8% 18% 13% 9% 5% 5% 6% 9% 11%	1565
	21st to end	Day	2 19% 9% 21% 10% 6% 6% 4 5% 6% 11%	2200
February	1st to 10th	Day	2 11% 4 17% 10% 8% 7% 5% 9% 7% 20%	1330
	11th to 20th	Day	2 12% 6% 17% 10% 8% 6% 3 7% 10% 19%	1462
	21st to end	Day	1 9% 6% 14% 10% 7% 9% 6% 8% 8% 22%	1413
March	1st to 10th	Day	7% 5% 15% 13% 13% 10% 6% 6% 7% 19%	2970
	11th to 20th	Day	1 11% 6% 16% 9% 9% 8% 5% 7% 8% 20%	3409
	21st to end	Day	1 8% 5% 17% 10% 8% 7% 5% 8% 8% 24%	4027
April	1st to 10th	Day	1 10% 6% 15% 8% 7% 7% 5% 9% 9% 23%	2372
	11th to 20th	Day	2 13% 4 12% 8% 6% 6% 5% 7% 8% 28%	2570
	21st to end	Day	3 11% 5% 10% 8% 7% 6% 6% 8% 10% 26%	2684
May	1st to 10th	Day	4 13% 4 10% 8% 7% 7% 5% 7% 9% 27%	4953
	11th to 20th	Day	4 11% 3 11% 7% 7% 7% 6% 9% 9% 26%	5013
	21st to end	Day	6% 9% 3 8% 7% 6% 6% 6% 9% 9% 30%	5772
June	1st to 10th	Day	9% 7% 3 8% 6% 6% 6% 6% 8% 9% 32%	3420
	11th to 20th	Day	12% 9% 4 8% 6% 5% 6% 5% 7% 9% 28%	3420
	21st to end	Day	8% 7% 3 8% 7% 6% 6% 6% 8% 8% 34%	3420
July	1st to 10th	Day	8% 8% 3 7% 6% 6% 7% 6% 8% 9% 33%	5579
	11th to 20th	Day	9% 8% 3 10% 7% 7% 7% 6% 8% 8% 26%	5380
	21st to end	Day	12% 9% 3 8% 6% 5% 6% 5% 7% 9% 31%	5591
August	1st to 10th	Day	8% 6% 2 6% 4 4 5% 5% 7% 8% 47%	4831
	11th to 20th	Day	10% 8% 3 7% 5% 5% 6% 4 7% 10% 35%	4504
	21st to end	Day	13% 10% 3 9% 6% 7% 7% 6% 8% 10% 21%	4767
September	1st to 10th	Day	15% 12% 4 10% 7% 5% 6% 4 6% 7% 24%	2367
	11th to 20th	Day	9% 11% 4 11% 6% 7% 6% 6% 8% 8% 25%	2280
	21st to end	Day	11% 14% 4 10% 6% 6% 7% 6% 7% 8% 21%	2006
October	1st to 10th	Day	7% 14% 5% 11% 7% 8% 8% 7% 8% 9% 16%	3170
	11th to 20th	Day	6% 11% 6% 15% 7% 6% 6% 6% 8% 10% 19%	2797
	21st to end	Day	4 15% 8% 16% 8% 8% 7% 6% 7% 8% 13%	2754
November	1st to 10th	Day	5% 16% 6% 23% 11% 8% 6% 3 6% 5% 11%	1372
	11th to 20th	Day	3 18% 9% 18% 11% 9% 7% 5% 7% 7% 8%	1146
	21st to end	Day	2 12% 7% 21% 10% 10% 7% 6% 7% 8% 10%	1131
December	1st to 10th	Day	3 12% 7% 19% 13% 8% 8% 5% 11% 6% 7%	775
	11th to 20th	Day	1 11% 5% 18% 14% 9% 10% 3 7% 9% 13%	962
	21st to end	Day	2 14% 8% 19% 14% 9% 8% 4 7% 6% 8%	1386
January	1st to 10th	Night	2 12% 7% 19% 13% 10% 9% 8% 6% 6% 9%	5399
	11th to 20th	Night	2 13% 6% 16% 11% 7% 7% 4 7% 14% 13%	5332
	21st to end	Night	3 17% 9% 20% 11% 8% 6% 4 6% 6% 11%	5459
February	1st to 10th	Night	2 11% 6% 15% 12% 10% 8% 5% 8% 7% 16%	2850
	11th to 20th	Night	2 12% 7% 17% 8% 6% 7% 5% 7% 8% 20%	2602
	21st to end	Night	2 10% 6% 13% 11% 6% 6% 5% 8% 10% 22%	2041
March	1st to 10th	Night	9% 5% 14% 12% 11% 11% 6% 6% 7% 19%	3894
	11th to 20th	Night	1 12% 6% 15% 9% 10% 9% 6% 8% 8% 17%	3548
	21st to end	Night	1 10% 6% 18% 7% 6% 6% 5% 7% 9% 24%	3610
April	1st to 10th	Night	1 6% 5% 12% 7% 8% 6% 5% 8% 10% 31%	1805
	11th to 20th	Night	1 11% 5% 12% 7% 7% 7% 5% 8% 9% 28%	1558
	21st to end	Night	2 7% 4 9% 7% 6% 8% 6% 10% 10% 31%	1496
May	1st to 10th	Night	2 6% 4 10% 6% 6% 7% 7% 9% 10% 33%	2010
	11th to 20th	Night	3 6% 2 10% 6% 7% 6% 6% 9% 11% 33%	1882
	21st to end	Night	4 10% 4 10% 7% 6% 6% 5% 8% 9% 31%	1800
June	1st to 10th	Night	9% 6% 3 6% 6% 6% 6% 5% 8% 11% 34%	760
	11th to 20th	Night	12% 9% 3 8% 5% 5% 5% 6% 8% 8% 30%	760
	21st to end	Night	6% 6% 3 7% 6% 7% 6% 7% 8% 9% 34%	760
July	1st to 10th	Night	5% 6% 2 6% 5% 4 6% 4 6% 10% 44%	1378
	11th to 20th	Night	9% 8% 2 8% 6% 8% 8% 4 8% 10% 30%	1580
	21st to end	Night	14% 7% 2 7% 5% 5% 6% 5% 8% 10% 31%	1961
August	1st to 10th	Night	6% 4 2 5% 4 5% 5% 5% 7% 8% 50%	2103
	11th to 20th	Night	13% 5% 3 5% 3 3 5% 3 7% 10% 43%	2334
	21st to end	Night	9% 8% 3 8% 8% 7% 6% 6% 7% 9% 29%	2887
September	1st to 10th	Night	13% 9% 2 9% 7% 6% 7% 6% 7% 9% 26%	1813
	11th to 20th	Night	7% 10% 3 9% 6% 6% 7% 5% 7% 9% 33%	1900
	21st to end	Night	9% 15% 4 10% 7% 5% 5% 5% 7% 7% 26%	2174
October	1st to 10th	Night	7% 15% 4 11% 6% 6% 7% 5% 8% 10% 21%	3800
	11th to 20th	Night	6% 14% 8% 17% 6% 5% 5% 4 5% 6% 24%	4131
	21st to end	Night	4 17% 8% 17% 8% 7% 6% 4 4 6% 19%	4805
November	1st to 10th	Night	4 15% 6% 19% 11% 8% 7% 5% 5% 6% 13%	2924
	11th to 20th	Night	3 16% 8% 21% 11% 8% 7% 4 5% 7% 10%	3056
	21st to end	Night	3 13% 5% 18% 12% 10% 8% 6% 7% 7% 10%	3040
December	1st to 10th	Night	4 13% 6% 18% 13% 9% 8% 5% 7% 6% 10%	3392
	11th to 20th	Night	2 13% 7% 18% 11% 9% 8% 6% 7% 7% 13%	4230
	21st to end	Night	4 17% 8% 17% 11% 9% 7% 5% 7% 7% 9%	6270

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	66% 13% 8% 4 7% 2	1561
	11th to 20th	Day	67% 6% 10% 8% 8% 1	1580
	21st to end	Day	71% 8% 7% 8% 5% 1	2200
February	1st to 10th	Day	58% 8% 9% 13% 11% 2	1330
	11th to 20th	Day	59% 9% 10% 10% 11%	1470
	21st to end	Day	54% 10% 13% 15% 8%	1413
March	1st to 10th	Day	59% 7% 12% 13% 8%	2970
	11th to 20th	Day	54% 14% 13% 10% 7% 3	3409
	21st to end	Day	50% 15% 17% 12% 5% 1	4027
April	1st to 10th	Day	54% 11% 17% 14% 4	2372
	11th to 20th	Day	51% 12% 12% 18% 7% 1	2570
	21st to end	Day	50% 13% 17% 16% 5%	2684
May	1st to 10th	Day	50% 12% 13% 20% 6%	4953
	11th to 20th	Day	47% 12% 16% 18% 7%	5016
	21st to end	Day	46% 10% 18% 17% 9%	5773
June	1st to 10th	Day	46% 12% 15% 19% 7% 1	3420
	11th to 20th	Day	50% 14% 15% 17% 3	3420
	21st to end	Day	45% 12% 17% 22% 4	3420
July	1st to 10th	Day	43% 12% 25% 17% 3	5493
	11th to 20th	Day	49% 11% 17% 19% 3	5287
	21st to end	Day	47% 12% 20% 18% 3	5414
August	1st to 10th	Day	34% 9% 24% 21% 11% 1	4812
	11th to 20th	Day	43% 12% 20% 21% 5%	4549
	21st to end	Day	53% 11% 20% 15% 1	4766
September	1st to 10th	Day	58% 11% 14% 15% 2	2367
	11th to 20th	Day	53% 13% 13% 18% 3	2280
	21st to end	Day	56% 13% 14% 14% 3	2006
October	1st to 10th	Day	57% 12% 13% 15% 2	3170
	11th to 20th	Day	56% 11% 18% 14% 2	2797
	21st to end	Day	62% 13% 12% 9% 3	2754
November	1st to 10th	Day	72% 8% 8% 8% 3	1372
	11th to 20th	Day	73% 10% 7% 8% 3	1146
	21st to end	Day	67% 11% 9% 6% 5%	1131
December	1st to 10th	Day	70% 14% 6% 7% 3	775
	11th to 20th	Day	65% 7% 8% 13% 6% 1	964
	21st to end	Day	69% 10% 9% 5% 6% 1	1386
January	1st to 10th	Night	69% 10% 7% 7% 5% 1	5399
	11th to 20th	Night	60% 7% 8% 11% 9% 4	5379
	21st to end	Night	70% 9% 7% 7% 5% 2	5459
February	1st to 10th	Night	61% 10% 9% 11% 8% 2	2850
	11th to 20th	Night	58% 10% 11% 11% 8% 1	2605
	21st to end	Night	53% 10% 13% 15% 9% 1	2041
March	1st to 10th	Night	59% 6% 12% 12% 11% 1	3894
	11th to 20th	Night	55% 15% 14% 10% 5%	3550
	21st to end	Night	52% 15% 15% 13% 4	3610
April	1st to 10th	Night	45% 12% 17% 19% 6%	1805
	11th to 20th	Night	48% 11% 15% 19% 7%	1558
	21st to end	Night	41% 14% 18% 21% 6%	1496
May	1st to 10th	Night	41% 12% 14% 26% 6% 1	2010
	11th to 20th	Night	38% 15% 15% 22% 10%	1882
	21st to end	Night	46% 9% 17% 24% 5%	1800
June	1st to 10th	Night	42% 10% 22% 21% 5%	760
	11th to 20th	Night	49% 14% 20% 15% 1	760
	21st to end	Night	42% 15% 18% 24% 2	760
July	1st to 10th	Night	33% 13% 36% 16% 2	1355
	11th to 20th	Night	46% 12% 19% 22% 1	1550
	21st to end	Night	46% 12% 24% 18% 1	1899
August	1st to 10th	Night	30% 13% 25% 23% 7% 2	2097
	11th to 20th	Night	36% 11% 22% 25% 6%	2355
	21st to end	Night	46% 14% 20% 20% 1	2887
September	1st to 10th	Night	52% 16% 17% 14% 1	1813
	11th to 20th	Night	46% 13% 19% 19% 3	1900
	21st to end	Night	54% 13% 14% 15% 4	2174
October	1st to 10th	Night	54% 11% 15% 18% 2	3800
	11th to 20th	Night	59% 9% 10% 20% 3	4131
	21st to end	Night	64% 11% 12% 10% 4	4805
November	1st to 10th	Night	69% 10% 8% 9% 3	2924
	11th to 20th	Night	72% 9% 7% 8% 3	3056
	21st to end	Night	68% 11% 9% 8% 3	3040
December	1st to 10th	Night	69% 12% 8% 8% 2	3392
	11th to 20th	Night	65% 10% 7% 11% 6% 1	4227
	21st to end	Night	69% 8% 9% 6% 6% 2	6270

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 2 18% 33% 30% 12%	90
	11th to 20th	Day	1 7% 13% 40% 22% 17%	90
	21st to end	Day	9% 11% 25% 29% 17% 10%	269
February	1st to 10th	Day	8% 8% 20% 34% 22% 8%	370
	11th to 20th	Day	5% 8% 26% 36% 13% 11%	365
	21st to end	Day	6% 6% 30% 33% 18% 8%	307
March	1st to 10th	Day	4 10% 27% 30% 19% 10%	370
	11th to 20th	Day	7% 11% 29% 30% 17% 5%	370
	21st to end	Day	5% 13% 29% 28% 18% 7%	466
April	1st to 10th	Day	5% 13% 31% 31% 16% 3	552
	11th to 20th	Day	9% 13% 24% 30% 20% 4	640
	21st to end	Day	8% 13% 26% 32% 17% 4	650
May	1st to 10th	Day	11% 21% 33% 23% 10% 2	653
	11th to 20th	Day	13% 16% 29% 24% 13% 5%	675
	21st to end	Day	12% 14% 35% 26% 11% 3	740
June	1st to 10th	Day	12% 10% 28% 29% 18% 4	870
	11th to 20th	Day	16% 11% 25% 27% 17% 3	870
	21st to end	Day	10% 10% 25% 29% 21% 5%	870
July	1st to 10th	Day	12% 8% 24% 29% 22% 5%	790
	11th to 20th	Day	13% 15% 27% 25% 16% 4	668
	21st to end	Day	17% 10% 27% 25% 17% 5%	739
August	1st to 10th	Day	14% 11% 27% 29% 15% 5%	676
	11th to 20th	Day	17% 21% 29% 20% 11% 2	665
	21st to end	Day	20% 14% 28% 23% 11% 3	748
September	1st to 10th	Day	22% 17% 24% 18% 14% 5%	577
	11th to 20th	Day	14% 15% 24% 23% 19% 5%	490
	21st to end	Day	21% 18% 25% 18% 11% 6%	407
October	1st to 10th	Day	20% 22% 20% 21% 12% 7%	390
	11th to 20th	Day	16% 12% 28% 26% 13% 5%	390
	21st to end	Day	11% 9% 22% 33% 20% 5%	429
November	1st to 10th	Day	9% 8% 28% 34% 17% 4	258
	11th to 20th	Day	14% 9% 16% 31% 20% 10%	182
	21st to end	Day	5% 11% 24% 34% 16% 9%	180
December	1st to 10th	Day	4 8% 21% 38% 18% 11%	97
	11th to 20th	Day	4 11% 12% 41% 20% 11%	90
	21st to end	Day	5% 12% 13% 33% 23% 13%	99
January	1st to 10th	Night	6% 3 24% 42% 20% 6%	870
	11th to 20th	Night	6% 7% 26% 38% 18% 5%	850
	21st to end	Night	8% 11% 27% 32% 18% 4	935
February	1st to 10th	Night	7% 6% 23% 44% 17% 3	850
	11th to 20th	Night	5% 8% 33% 33% 17% 4	834
	21st to end	Night	7% 7% 27% 41% 15% 4	703
March	1st to 10th	Night	5% 8% 28% 34% 20% 4	805
	11th to 20th	Night	5% 8% 26% 34% 25% 3	614
	21st to end	Night	5% 7% 25% 34% 25% 3	627
April	1st to 10th	Night	3 6% 25% 35% 27% 4	570
	11th to 20th	Night	6% 4 23% 32% 31% 4	563
	21st to end	Night	5% 5% 20% 34% 33% 4	570
May	1st to 10th	Night	8% 10% 20% 31% 28% 2	451
	11th to 20th	Night	9% 8% 24% 34% 24% 1	374
	21st to end	Night	8% 5% 23% 36% 27% 1	267
June	1st to 10th	Night	12% 1 21% 41% 26%	190
	11th to 20th	Night	16% 5% 18% 41% 21%	190
	21st to end	Night	8% 4 23% 39% 25% 1	190
July	1st to 10th	Night	8% 4 22% 38% 29%	185
	11th to 20th	Night	14% 4 17% 39% 26%	184
	21st to end	Night	14% 7% 21% 32% 25% 1	350
August	1st to 10th	Night	9% 6% 27% 37% 20% 1	497
	11th to 20th	Night	18% 8% 26% 27% 19% 2	564
	21st to end	Night	18% 6% 21% 33% 19% 1	627
September	1st to 10th	Night	19% 10% 24% 26% 19% 2	570
	11th to 20th	Night	14% 9% 23% 30% 22% 3	570
	21st to end	Night	18% 11% 24% 26% 17% 4	687
October	1st to 10th	Night	18% 12% 26% 27% 16% 2	760
	11th to 20th	Night	16% 8% 25% 32% 16% 2	803
	21st to end	Night	9% 6% 30% 33% 19% 2	946
November	1st to 10th	Night	12% 5% 26% 38% 16% 3	880
	11th to 20th	Night	11% 8% 23% 34% 20% 6%	855
	21st to end	Night	9% 10% 27% 32% 19% 4	850
December	1st to 10th	Night	9% 7% 25% 33% 22% 4	1030
	11th to 20th	Night	10% 7% 22% 33% 20% 8%	1040
	21st to end	Night	10% 7% 22% 33% 21% 7%	1144

Page generated at 2024-11-08 19:45:41. Version ac07

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