Kluane Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kluane Lake clear sky chart from 2005-11-06 to 2024-12-09.

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% 7% 3 9% 7% 7% 7% 6% 8% 10% 30%	106553
	Night	4 8% 4 11% 8% 7% 8% 6% 9% 10% 26%	101755
Transparency	Day	44% 15% 17% 17% 6% 1	106246
	Night	43% 15% 14% 17% 8% 2	101709
Seeing	Day	10% 11% 26% 28% 19% 6%	17149
	Night	7% 8% 25% 32% 22% 6%	23001

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	3 1 10% 9% 10% 10% 7% 10% 11% 28%	1551
	11th to 20th	Day	1 6% 3 12% 11% 9% 7% 6% 11% 10% 24%	1565
	21st to end	Day	4 2 8% 8% 10% 13% 9% 10% 11% 26%	2094
February	1st to 10th	Day	1 4 4 7% 7% 8% 8% 6% 8% 12% 35%	1330
	11th to 20th	Day	1 5% 4 9% 7% 5% 7% 6% 9% 12% 33%	1439
	21st to end	Day	4 4 10% 9% 10% 8% 7% 8% 9% 31%	1413
March	1st to 10th	Day	3 2 10% 12% 12% 8% 6% 8% 10% 29%	2922
	11th to 20th	Day	4 3 8% 8% 7% 8% 6% 10% 12% 33%	3467
	21st to end	Day	3 2 6% 6% 6% 7% 7% 10% 16% 37%	3988
April	1st to 10th	Day	7% 4 11% 6% 5% 6% 6% 9% 12% 32%	2418
	11th to 20th	Day	2 10% 4 9% 6% 6% 6% 6% 8% 9% 35%	2550
	21st to end	Day	1 7% 4 8% 5% 6% 7% 6% 8% 10% 37%	2739
May	1st to 10th	Day	1 5% 2 9% 6% 6% 6% 6% 9% 12% 37%	4928
	11th to 20th	Day	3 8% 3 8% 5% 6% 7% 6% 8% 12% 33%	5040
	21st to end	Day	6% 8% 3 7% 5% 6% 6% 6% 9% 11% 32%	5879
June	1st to 10th	Day	10% 8% 3 7% 6% 6% 6% 5% 8% 10% 31%	3420
	11th to 20th	Day	14% 10% 3 9% 7% 6% 6% 5% 7% 9% 24%	3420
	21st to end	Day	11% 7% 3 8% 7% 6% 8% 6% 9% 9% 26%	3420
July	1st to 10th	Day	11% 7% 3 8% 7% 6% 8% 6% 7% 9% 27%	5588
	11th to 20th	Day	10% 7% 2 7% 6% 7% 7% 6% 9% 11% 28%	5380
	21st to end	Day	15% 9% 3 8% 6% 6% 5% 5% 7% 9% 27%	5717
August	1st to 10th	Day	8% 5% 2 5% 4 5% 6% 5% 7% 9% 45%	4808
	11th to 20th	Day	12% 7% 2 6% 5% 6% 5% 5% 7% 9% 35%	4591
	21st to end	Day	12% 11% 3 8% 6% 7% 7% 6% 8% 9% 22%	4729
September	1st to 10th	Day	9% 8% 4 8% 7% 7% 7% 4 7% 10% 30%	2404
	11th to 20th	Day	6% 8% 3 7% 6% 5% 6% 6% 8% 9% 36%	2275
	21st to end	Day	6% 12% 3 8% 5% 6% 6% 6% 7% 10% 30%	2003
October	1st to 10th	Day	4 9% 3 9% 8% 8% 8% 7% 9% 10% 24%	3170
	11th to 20th	Day	2 8% 4 13% 8% 7% 7% 5% 7% 10% 29%	2760
	21st to end	Day	4 12% 5% 16% 8% 8% 8% 5% 8% 8% 18%	2754
November	1st to 10th	Day	1 9% 7% 15% 8% 7% 7% 6% 7% 10% 23%	1331
	11th to 20th	Day	1 8% 6% 15% 14% 9% 9% 8% 11% 7% 15%	1200
	21st to end	Day	1 7% 4 12% 6% 8% 10% 9% 11% 13% 19%	1120
December	1st to 10th	Day	1 6% 5% 12% 7% 8% 8% 10% 11% 11% 21%	792
	11th to 20th	Day	4 2 10% 7% 6% 8% 8% 11% 11% 32%	962
	21st to end	Day	5% 3 9% 6% 7% 9% 8% 11% 14% 28%	1386
January	1st to 10th	Night	5% 3 9% 8% 8% 8% 6% 10% 13% 30%	5422
	11th to 20th	Night	7% 5% 11% 9% 7% 8% 7% 9% 11% 26%	5333
	21st to end	Night	4 3 10% 8% 9% 11% 9% 11% 11% 23%	5566
February	1st to 10th	Night	1 6% 3 10% 9% 8% 8% 6% 10% 13% 27%	2850
	11th to 20th	Night	5% 3 10% 7% 6% 9% 7% 10% 13% 28%	2626
	21st to end	Night	6% 3 13% 10% 8% 9% 7% 9% 11% 24%	2041
March	1st to 10th	Night	5% 4 14% 11% 11% 9% 7% 9% 10% 20%	3942
	11th to 20th	Night	1 9% 4 12% 9% 9% 8% 6% 8% 11% 24%	3489
	21st to end	Night	1 5% 3 13% 8% 7% 7% 6% 9% 14% 27%	3648
April	1st to 10th	Night	1 8% 5% 13% 6% 6% 6% 4 8% 12% 31%	1762
	11th to 20th	Night	1 11% 5% 9% 6% 5% 7% 5% 9% 9% 33%	1579
	21st to end	Night	2 9% 5% 9% 6% 5% 5% 6% 8% 10% 34%	1439
May	1st to 10th	Night	2 6% 2 8% 6% 6% 7% 7% 9% 14% 34%	2036
	11th to 20th	Night	5% 9% 3 7% 6% 5% 6% 6% 7% 9% 38%	1853
	21st to end	Night	10% 11% 4 8% 6% 6% 7% 4 7% 9% 28%	1695
June	1st to 10th	Night	11% 6% 3 7% 6% 6% 6% 7% 8% 10% 30%	760
	11th to 20th	Night	16% 10% 4 9% 6% 6% 5% 4 8% 8% 25%	760
	21st to end	Night	13% 8% 3 6% 6% 7% 9% 5% 9% 13% 21%	760
July	1st to 10th	Night	17% 10% 3 9% 6% 7% 6% 4 6% 9% 25%	1356
	11th to 20th	Night	10% 7% 3 8% 7% 6% 8% 6% 8% 11% 26%	1580
	21st to end	Night	20% 11% 2 8% 4 5% 4 5% 6% 8% 26%	1835
August	1st to 10th	Night	11% 5% 2 6% 5% 4 5% 5% 8% 8% 42%	2116
	11th to 20th	Night	16% 8% 3 6% 4 4 4 4 7% 9% 36%	2247
	21st to end	Night	11% 10% 3 9% 6% 7% 7% 7% 7% 7% 27%	2935
September	1st to 10th	Night	11% 8% 3 8% 6% 5% 6% 5% 8% 8% 31%	1776
	11th to 20th	Night	7% 7% 3 8% 5% 6% 6% 6% 8% 9% 36%	1905
	21st to end	Night	8% 15% 3 8% 5% 6% 6% 5% 8% 7% 28%	2176
October	1st to 10th	Night	4 12% 4 10% 6% 7% 7% 4 7% 11% 28%	3800
	11th to 20th	Night	3 10% 5% 18% 7% 6% 8% 4 6% 8% 25%	4166
	21st to end	Night	3 12% 7% 20% 10% 9% 7% 4 6% 5% 17%	4805
November	1st to 10th	Night	1 11% 5% 12% 10% 8% 8% 6% 8% 11% 20%	2966
	11th to 20th	Night	1 10% 7% 16% 12% 8% 8% 5% 7% 10% 16%	3200
	21st to end	Night	2 7% 3 11% 8% 7% 9% 7% 12% 13% 20%	3270
December	1st to 10th	Night	1 5% 4 12% 9% 7% 9% 9% 10% 11% 24%	3561
	11th to 20th	Night	5% 3 10% 9% 8% 8% 7% 9% 11% 30%	4230
	21st to end	Night	1 6% 4 10% 7% 8% 9% 7% 11% 12% 26%	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	37% 11% 12% 20% 16% 3	1551
	11th to 20th	Day	44% 14% 10% 16% 10% 6%	1580
	21st to end	Day	32% 20% 19% 17% 10% 2	2094
February	1st to 10th	Day	37% 12% 11% 17% 17% 6%	1330
	11th to 20th	Day	37% 15% 15% 15% 12% 5%	1446
	21st to end	Day	45% 12% 11% 16% 11% 4	1413
March	1st to 10th	Day	39% 17% 11% 17% 16% 1	2922
	11th to 20th	Day	36% 17% 18% 15% 11% 3	3467
	21st to end	Day	29% 20% 22% 20% 7% 3	3988
April	1st to 10th	Day	44% 16% 16% 16% 6% 1	2418
	11th to 20th	Day	44% 14% 16% 17% 8% 1	2550
	21st to end	Day	39% 17% 21% 18% 6%	2739
May	1st to 10th	Day	36% 16% 18% 22% 8% 1	4928
	11th to 20th	Day	39% 16% 17% 20% 7% 1	5043
	21st to end	Day	40% 16% 18% 18% 8%	5880
June	1st to 10th	Day	48% 14% 18% 13% 7%	3420
	11th to 20th	Day	57% 13% 15% 12% 4	3420
	21st to end	Day	52% 15% 17% 14% 2	3420
July	1st to 10th	Day	49% 13% 21% 13% 3	5502
	11th to 20th	Day	46% 14% 17% 20% 4	5287
	21st to end	Day	51% 12% 19% 16% 2	5536
August	1st to 10th	Day	34% 13% 23% 20% 10% 1	4789
	11th to 20th	Day	44% 11% 20% 22% 2	4636
	21st to end	Day	54% 12% 16% 16% 1	4728
September	1st to 10th	Day	51% 14% 14% 17% 4	2404
	11th to 20th	Day	42% 16% 18% 20% 4	2275
	21st to end	Day	48% 15% 15% 18% 4	2003
October	1st to 10th	Day	48% 14% 15% 18% 5%	3170
	11th to 20th	Day	45% 14% 17% 19% 5%	2760
	21st to end	Day	52% 16% 17% 10% 4 1	2754
November	1st to 10th	Day	49% 12% 14% 16% 8% 2	1331
	11th to 20th	Day	59% 11% 9% 14% 7% 1	1200
	21st to end	Day	46% 15% 14% 15% 10% 1	1120
December	1st to 10th	Day	48% 15% 14% 17% 6% 1	792
	11th to 20th	Day	37% 14% 10% 17% 20% 2	964
	21st to end	Day	33% 20% 14% 18% 13% 3	1386
January	1st to 10th	Night	35% 14% 13% 24% 12% 3	5422
	11th to 20th	Night	41% 14% 12% 15% 11% 7%	5380
	21st to end	Night	34% 22% 14% 18% 11% 2	5566
February	1st to 10th	Night	41% 11% 12% 17% 14% 5%	2850
	11th to 20th	Night	39% 14% 14% 16% 13% 4	2630
	21st to end	Night	45% 10% 13% 18% 10% 4	2041
March	1st to 10th	Night	44% 13% 10% 17% 14% 1	3942
	11th to 20th	Night	42% 17% 13% 14% 12% 2	3491
	21st to end	Night	30% 21% 22% 19% 6% 2	3648
April	1st to 10th	Night	42% 14% 18% 18% 8% 1	1762
	11th to 20th	Night	43% 13% 17% 17% 8% 1	1579
	21st to end	Night	40% 17% 19% 17% 8%	1439
May	1st to 10th	Night	33% 17% 18% 21% 9% 1	2036
	11th to 20th	Night	34% 16% 17% 24% 9%	1853
	21st to end	Night	46% 16% 15% 17% 7%	1695
June	1st to 10th	Night	45% 14% 19% 18% 4	760
	11th to 20th	Night	53% 13% 16% 14% 3	760
	21st to end	Night	50% 17% 19% 13% 1	760
July	1st to 10th	Night	50% 12% 21% 14% 3	1333
	11th to 20th	Night	45% 12% 20% 23%	1550
	21st to end	Night	52% 11% 19% 17% 1	1777
August	1st to 10th	Night	37% 12% 21% 20% 9% 1	2110
	11th to 20th	Night	44% 9% 19% 24% 4	2268
	21st to end	Night	51% 13% 14% 20% 2	2935
September	1st to 10th	Night	48% 15% 18% 16% 3	1776
	11th to 20th	Night	42% 15% 19% 20% 5%	1905
	21st to end	Night	50% 13% 16% 14% 6% 1	2176
October	1st to 10th	Night	45% 13% 13% 25% 4 1	3800
	11th to 20th	Night	52% 15% 9% 17% 6% 1	4166
	21st to end	Night	57% 16% 12% 10% 4 1	4805
November	1st to 10th	Night	50% 15% 13% 15% 7% 1	2966
	11th to 20th	Night	57% 11% 10% 14% 7% 1	3200
	21st to end	Night	44% 16% 15% 17% 8% 1	3270
December	1st to 10th	Night	45% 15% 14% 18% 7% 1	3561
	11th to 20th	Night	40% 13% 12% 17% 15% 2	4227
	21st to end	Night	36% 21% 12% 14% 13% 3	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	1 11% 16% 33% 28% 11%	90
	11th to 20th	Day	2 6% 23% 30% 29% 10%	90
	21st to end	Day	6% 10% 29% 30% 17% 8%	242
February	1st to 10th	Day	4 8% 25% 34% 23% 7%	370
	11th to 20th	Day	1 13% 31% 33% 13% 9%	365
	21st to end	Day	3 9% 33% 35% 13% 7%	307
March	1st to 10th	Day	2 10% 27% 27% 22% 12%	370
	11th to 20th	Day	2 12% 34% 26% 20% 6%	370
	21st to end	Day	2 10% 32% 28% 22% 6%	454
April	1st to 10th	Day	2 11% 30% 32% 21% 3	598
	11th to 20th	Day	5% 11% 22% 33% 25% 5%	640
	21st to end	Day	5% 10% 23% 33% 24% 5%	650
May	1st to 10th	Day	8% 14% 32% 29% 15% 3	653
	11th to 20th	Day	8% 12% 25% 29% 18% 7%	675
	21st to end	Day	10% 12% 27% 32% 15% 4	744
June	1st to 10th	Day	13% 9% 26% 29% 19% 5%	870
	11th to 20th	Day	16% 9% 24% 27% 19% 5%	870
	21st to end	Day	13% 9% 20% 27% 24% 7%	870
July	1st to 10th	Day	14% 6% 22% 29% 23% 6%	799
	11th to 20th	Day	17% 12% 22% 27% 18% 4	668
	21st to end	Day	14% 9% 22% 29% 20% 5%	739
August	1st to 10th	Day	13% 9% 26% 25% 22% 6%	676
	11th to 20th	Day	17% 16% 25% 23% 15% 4	665
	21st to end	Day	16% 13% 27% 27% 16% 2	748
September	1st to 10th	Day	15% 16% 22% 23% 17% 6%	614
	11th to 20th	Day	13% 15% 24% 25% 18% 5%	487
	21st to end	Day	15% 19% 27% 21% 9% 9%	390
October	1st to 10th	Day	11% 20% 31% 20% 13% 6%	390
	11th to 20th	Day	10% 17% 29% 23% 15% 6%	390
	21st to end	Day	7% 10% 28% 33% 19% 3	429
November	1st to 10th	Day	8% 10% 28% 34% 14% 6%	274
	11th to 20th	Day	4 12% 16% 32% 28% 9%	200
	21st to end	Day	4 11% 28% 24% 21% 12%	165
December	1st to 10th	Day	3 12% 20% 31% 21% 12%	98
	11th to 20th	Day	4 6% 17% 40% 28% 6%	90
	21st to end	Day	4 14% 18% 26% 24% 13%	99
January	1st to 10th	Night	2 7% 25% 35% 25% 6%	880
	11th to 20th	Night	2 8% 32% 32% 21% 4	850
	21st to end	Night	4 8% 32% 31% 18% 6%	935
February	1st to 10th	Night	2 8% 26% 38% 22% 3	850
	11th to 20th	Night	2 10% 33% 32% 17% 5%	834
	21st to end	Night	2 8% 28% 39% 19% 5%	703
March	1st to 10th	Night	2 6% 29% 31% 24% 8%	820
	11th to 20th	Night	5% 9% 24% 32% 21% 10%	581
	21st to end	Night	3 7% 24% 31% 27% 8%	627
April	1st to 10th	Night	4 7% 21% 34% 29% 6%	570
	11th to 20th	Night	5% 5% 22% 31% 30% 7%	563
	21st to end	Night	6% 5% 20% 31% 31% 7%	570
May	1st to 10th	Night	5% 9% 27% 30% 25% 4	464
	11th to 20th	Night	11% 9% 24% 28% 26% 2	358
	21st to end	Night	9% 5% 19% 30% 29% 7%	206
June	1st to 10th	Night	15% 3 24% 29% 26% 3	190
	11th to 20th	Night	17% 5% 17% 32% 27% 1	190
	21st to end	Night	16% 5% 17% 33% 28% 2	190
July	1st to 10th	Night	18% 2 19% 33% 28% 1	185
	11th to 20th	Night	19% 8% 18% 25% 26% 5%	184
	21st to end	Night	17% 6% 15% 32% 25% 6%	276
August	1st to 10th	Night	11% 7% 21% 32% 25% 5%	510
	11th to 20th	Night	18% 8% 22% 27% 20% 6%	564
	21st to end	Night	17% 8% 19% 31% 21% 4	627
September	1st to 10th	Night	18% 11% 22% 27% 18% 4	570
	11th to 20th	Night	12% 9% 22% 32% 21% 4	570
	21st to end	Night	16% 15% 22% 25% 15% 7%	656
October	1st to 10th	Night	12% 15% 27% 28% 14% 4	760
	11th to 20th	Night	12% 10% 24% 30% 18% 6%	827
	21st to end	Night	6% 7% 27% 36% 19% 4	946
November	1st to 10th	Night	5% 9% 27% 34% 18% 6%	880
	11th to 20th	Night	4 8% 25% 33% 23% 7%	900
	21st to end	Night	5% 11% 28% 27% 20% 9%	900
December	1st to 10th	Night	3 11% 25% 33% 22% 6%	1081
	11th to 20th	Night	5% 7% 24% 35% 22% 8%	1040
	21st to end	Night	4 7% 28% 30% 20% 11%	1144

Page generated at 2024-12-06 00:54:50. Version ac07

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