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 2024-01-16.

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% 4 7% 8% 5% 7% 8% 8% 10% 30%	74332
	Night	4 7% 4 9% 9% 5% 8% 8% 9% 11% 26%	75478
Transparency	Day	47% 15% 17% 15% 6% 1	73965
	Night	45% 15% 15% 16% 8% 2	75364
Seeing	Day	10% 11% 26% 28% 19% 5%	15861
	Night	7% 8% 25% 32% 22% 6%	21934

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 3 3 8% 10% 7% 12% 8% 9% 13% 26%	934
	11th to 20th	Day	1 3 3 10% 10% 9% 11% 10% 11% 12% 20%	925
	21st to end	Day	1 6% 3 10% 9% 5% 11% 13% 10% 12% 20%	1192
February	1st to 10th	Day	1 3 5% 7% 7% 5% 9% 8% 8% 12% 35%	1260
	11th to 20th	Day	1 4 6% 9% 7% 4 7% 8% 9% 12% 32%	1362
	21st to end	Day	4 5% 9% 9% 6% 11% 8% 8% 10% 31%	1332
March	1st to 10th	Day	3 4 9% 10% 6% 9% 9% 9% 11% 30%	1676
	11th to 20th	Day	4 5% 7% 11% 5% 9% 8% 10% 11% 28%	1967
	21st to end	Day	1 4 3 7% 7% 5% 8% 7% 9% 14% 35%	2269
April	1st to 10th	Day	1 7% 4 9% 8% 4 6% 7% 9% 12% 33%	2290
	11th to 20th	Day	2 9% 5% 8% 6% 5% 6% 7% 8% 9% 33%	2414
	21st to end	Day	2 7% 4 6% 6% 4 7% 7% 8% 10% 38%	2594
May	1st to 10th	Day	3 6% 3 6% 8% 5% 7% 8% 9% 12% 34%	2800
	11th to 20th	Day	6% 8% 3 6% 6% 4 6% 8% 7% 10% 37%	2846
	21st to end	Day	6% 7% 3 5% 5% 4 6% 6% 8% 12% 38%	3313
June	1st to 10th	Day	10% 7% 3 6% 7% 4 7% 6% 8% 10% 32%	3240
	11th to 20th	Day	14% 9% 4 8% 7% 5% 7% 6% 7% 9% 24%	3240
	21st to end	Day	11% 7% 3 7% 8% 5% 8% 8% 9% 9% 26%	3240
July	1st to 10th	Day	12% 6% 3 7% 8% 5% 7% 7% 8% 9% 28%	3184
	11th to 20th	Day	15% 8% 3 7% 8% 5% 8% 7% 8% 11% 22%	3060
	21st to end	Day	14% 7% 4 7% 6% 4 6% 6% 8% 10% 29%	3268
August	1st to 10th	Day	12% 6% 3 5% 6% 4 6% 7% 7% 10% 33%	2740
	11th to 20th	Day	10% 8% 4 7% 7% 5% 7% 8% 7% 9% 29%	2619
	21st to end	Day	15% 9% 3 6% 8% 5% 7% 7% 7% 9% 24%	2693
September	1st to 10th	Day	9% 8% 4 7% 8% 5% 7% 6% 7% 9% 29%	2278
	11th to 20th	Day	6% 7% 3 6% 7% 4 6% 7% 8% 10% 35%	2156
	21st to end	Day	6% 12% 3 7% 7% 5% 6% 7% 7% 10% 30%	1898
October	1st to 10th	Day	6% 10% 3 7% 8% 4 7% 8% 8% 9% 30%	1800
	11th to 20th	Day	4 10% 6% 10% 8% 5% 7% 6% 6% 9% 30%	1581
	21st to end	Day	2 12% 5% 9% 8% 7% 9% 8% 8% 8% 24%	1584
November	1st to 10th	Day	1 8% 7% 14% 9% 6% 7% 8% 7% 10% 23%	1264
	11th to 20th	Day	1 7% 6% 13% 15% 7% 10% 9% 10% 7% 14%	1140
	21st to end	Day	1 5% 5% 10% 7% 5% 13% 10% 10% 15% 20%	1065
December	1st to 10th	Day	1 6% 6% 9% 10% 5% 10% 11% 11% 12% 19%	760
	11th to 20th	Day	4 2 9% 8% 4 8% 10% 10% 12% 32%	962
	21st to end	Day	5% 3 8% 7% 5% 9% 10% 11% 14% 29%	1386
January	1st to 10th	Night	4 3 8% 9% 7% 9% 9% 10% 13% 28%	3246
	11th to 20th	Night	5% 4 6% 9% 7% 11% 10% 9% 13% 24%	3157
	21st to end	Night	6% 4 10% 10% 7% 11% 10% 10% 12% 20%	3164
February	1st to 10th	Night	1 5% 3 8% 10% 6% 8% 8% 10% 13% 27%	2700
	11th to 20th	Night	5% 4 10% 8% 5% 8% 9% 10% 13% 28%	2483
	21st to end	Night	5% 4 11% 9% 6% 9% 9% 8% 11% 25%	1924
March	1st to 10th	Night	5% 4 11% 10% 6% 9% 8% 9% 11% 26%	2284
	11th to 20th	Night	1 6% 5% 10% 13% 8% 10% 7% 7% 11% 23%	1989
	21st to end	Night	2 6% 3 11% 9% 5% 7% 8% 7% 14% 29%	2086
April	1st to 10th	Night	1 8% 5% 11% 7% 5% 6% 6% 7% 12% 32%	1670
	11th to 20th	Night	2 11% 5% 8% 7% 4 6% 7% 8% 9% 32%	1495
	21st to end	Night	2 9% 5% 8% 6% 4 5% 7% 8% 11% 35%	1364
May	1st to 10th	Night	3 8% 2 7% 7% 4 7% 8% 8% 12% 35%	1160
	11th to 20th	Night	8% 11% 3 6% 4 2 6% 7% 7% 8% 38%	1047
	21st to end	Night	9% 7% 4 6% 5% 4 7% 6% 7% 12% 33%	961
June	1st to 10th	Night	11% 6% 3 6% 7% 4 6% 8% 7% 11% 31%	720
	11th to 20th	Night	17% 8% 4 7% 8% 4 6% 6% 7% 8% 26%	720
	21st to end	Night	13% 7% 4 6% 6% 5% 8% 7% 10% 14% 20%	720
July	1st to 10th	Night	15% 7% 3 7% 6% 6% 6% 5% 7% 8% 30%	774
	11th to 20th	Night	17% 8% 3 8% 8% 3 6% 6% 6% 9% 23%	900
	21st to end	Night	18% 9% 2 6% 5% 4 4 6% 7% 10% 30%	1049
August	1st to 10th	Night	13% 6% 3 7% 7% 4 5% 6% 8% 10% 31%	1199
	11th to 20th	Night	12% 8% 3 6% 7% 4 6% 6% 6% 10% 31%	1281
	21st to end	Night	14% 9% 3 8% 6% 5% 7% 9% 8% 9% 23%	1660
September	1st to 10th	Night	11% 8% 3 7% 7% 4 6% 7% 8% 8% 31%	1682
	11th to 20th	Night	7% 7% 2 6% 6% 4 6% 7% 8% 9% 37%	1804
	21st to end	Night	8% 15% 3 6% 6% 4 6% 7% 8% 7% 29%	2061
October	1st to 10th	Night	6% 12% 4 9% 7% 5% 8% 6% 6% 8% 30%	2160
	11th to 20th	Night	5% 14% 6% 13% 7% 5% 7% 5% 6% 8% 24%	2377
	21st to end	Night	3 10% 6% 12% 10% 7% 10% 6% 7% 7% 21%	2772
November	1st to 10th	Night	1 10% 6% 11% 11% 6% 8% 8% 8% 11% 20%	2813
	11th to 20th	Night	1 9% 7% 14% 13% 6% 9% 8% 7% 10% 17%	3040
	21st to end	Night	2 7% 3 9% 9% 5% 9% 9% 12% 15% 20%	3106
December	1st to 10th	Night	1 5% 4 11% 10% 5% 9% 10% 9% 12% 23%	3410
	11th to 20th	Night	1 5% 3 8% 10% 5% 8% 9% 9% 12% 30%	4230
	21st to end	Night	1 6% 4 9% 8% 5% 9% 9% 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	43% 11% 15% 16% 11% 5%	934
	11th to 20th	Day	47% 17% 13% 15% 6% 2	925
	21st to end	Day	45% 13% 16% 15% 10% 1	1192
February	1st to 10th	Day	37% 12% 11% 17% 17% 6%	1260
	11th to 20th	Day	39% 15% 16% 15% 11% 4	1369
	21st to end	Day	45% 13% 11% 17% 10% 4	1332
March	1st to 10th	Day	44% 14% 14% 15% 11% 2	1676
	11th to 20th	Day	46% 17% 13% 13% 9% 2	1967
	21st to end	Day	39% 17% 17% 15% 8% 2	2269
April	1st to 10th	Day	44% 16% 17% 16% 6% 1	2290
	11th to 20th	Day	45% 15% 16% 16% 7%	2414
	21st to end	Day	40% 16% 21% 17% 6%	2594
May	1st to 10th	Day	43% 16% 20% 16% 4	2800
	11th to 20th	Day	43% 14% 15% 19% 8%	2849
	21st to end	Day	39% 15% 21% 19% 5%	3314
June	1st to 10th	Day	49% 14% 18% 13% 7%	3240
	11th to 20th	Day	58% 13% 15% 11% 4	3240
	21st to end	Day	53% 16% 17% 12% 2	3240
July	1st to 10th	Day	52% 14% 16% 13% 5%	3098
	11th to 20th	Day	56% 17% 17% 8% 2	2967
	21st to end	Day	50% 16% 20% 11% 2	3086
August	1st to 10th	Day	45% 17% 20% 15% 3	2721
	11th to 20th	Day	51% 15% 19% 13% 2	2619
	21st to end	Day	58% 15% 16% 10% 1	2693
September	1st to 10th	Day	52% 14% 14% 16% 3	2278
	11th to 20th	Day	42% 17% 18% 19% 3	2156
	21st to end	Day	49% 15% 16% 16% 4	1898
October	1st to 10th	Day	49% 15% 16% 14% 5%	1800
	11th to 20th	Day	49% 15% 18% 12% 6%	1581
	21st to end	Day	51% 13% 14% 14% 7% 1	1584
November	1st to 10th	Day	49% 12% 15% 15% 7% 2	1264
	11th to 20th	Day	59% 11% 9% 14% 7% 1	1140
	21st to end	Day	45% 15% 14% 15% 10% 1	1065
December	1st to 10th	Day	50% 14% 14% 16% 5% 1	760
	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	40% 14% 15% 15% 12% 4	3246
	11th to 20th	Night	42% 16% 15% 15% 9% 2	3157
	21st to end	Night	45% 15% 13% 16% 9% 1	3164
February	1st to 10th	Night	42% 10% 12% 17% 14% 5%	2700
	11th to 20th	Night	40% 14% 14% 17% 11% 4	2487
	21st to end	Night	46% 10% 13% 18% 10% 4	1924
March	1st to 10th	Night	44% 10% 11% 19% 15% 2	2284
	11th to 20th	Night	51% 13% 12% 14% 10% 1	1991
	21st to end	Night	42% 14% 17% 16% 8% 3	2086
April	1st to 10th	Night	42% 14% 18% 18% 7% 1	1670
	11th to 20th	Night	44% 14% 18% 17% 7%	1495
	21st to end	Night	40% 16% 19% 17% 8%	1364
May	1st to 10th	Night	42% 16% 19% 18% 6%	1160
	11th to 20th	Night	42% 13% 13% 19% 12%	1047
	21st to end	Night	43% 14% 19% 20% 4	961
June	1st to 10th	Night	45% 13% 19% 18% 4	720
	11th to 20th	Night	53% 13% 16% 14% 3	720
	21st to end	Night	50% 18% 20% 12%	720
July	1st to 10th	Night	46% 14% 18% 17% 5%	751
	11th to 20th	Night	56% 16% 17% 11% 1	870
	21st to end	Night	48% 15% 24% 11% 2	991
August	1st to 10th	Night	45% 16% 21% 16% 2	1193
	11th to 20th	Night	50% 13% 21% 15% 1	1281
	21st to end	Night	55% 16% 18% 11% 1	1660
September	1st to 10th	Night	48% 15% 18% 16% 3	1682
	11th to 20th	Night	41% 15% 19% 19% 5%	1804
	21st to end	Night	50% 14% 16% 14% 5% 1	2061
October	1st to 10th	Night	50% 13% 14% 16% 6% 1	2160
	11th to 20th	Night	55% 15% 14% 10% 5% 1	2377
	21st to end	Night	54% 13% 14% 13% 5% 2	2772
November	1st to 10th	Night	51% 15% 12% 14% 7% 1	2813
	11th to 20th	Night	56% 12% 11% 14% 7% 1	3040
	21st to end	Night	43% 16% 15% 18% 8% 1	3106
December	1st to 10th	Night	46% 16% 14% 17% 7% 1	3410
	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 5% 25% 27% 31% 11%	85
	21st to end	Day	4 9% 30% 30% 18% 9%	220
February	1st to 10th	Day	3 8% 25% 34% 22% 7%	340
	11th to 20th	Day	1 14% 31% 31% 12% 10%	335
	21st to end	Day	2 9% 34% 35% 13% 8%	280
March	1st to 10th	Day	2 11% 28% 24% 22% 13%	340
	11th to 20th	Day	1 11% 35% 26% 20% 7%	340
	21st to end	Day	2 9% 33% 29% 21% 5%	415
April	1st to 10th	Day	2 11% 29% 32% 23% 3	550
	11th to 20th	Day	6% 11% 22% 32% 24% 5%	590
	21st to end	Day	5% 11% 25% 34% 22% 4	600
May	1st to 10th	Day	7% 13% 32% 30% 16% 3	603
	11th to 20th	Day	9% 11% 25% 29% 19% 7%	625
	21st to end	Day	10% 12% 27% 32% 15% 4	688
June	1st to 10th	Day	13% 8% 25% 28% 21% 5%	810
	11th to 20th	Day	16% 9% 25% 28% 18% 3	810
	21st to end	Day	14% 9% 21% 27% 24% 4	810
July	1st to 10th	Day	14% 6% 23% 27% 23% 7%	743
	11th to 20th	Day	18% 11% 21% 27% 19% 4	618
	21st to end	Day	14% 10% 23% 28% 20% 5%	684
August	1st to 10th	Day	13% 9% 27% 24% 21% 5%	626
	11th to 20th	Day	17% 17% 26% 22% 14% 4	615
	21st to end	Day	16% 13% 26% 27% 16% 2	693
September	1st to 10th	Day	16% 16% 23% 23% 16% 5%	568
	11th to 20th	Day	13% 15% 24% 25% 18% 5%	448
	21st to end	Day	16% 20% 28% 21% 8% 7%	360
October	1st to 10th	Day	12% 19% 32% 19% 12% 5%	360
	11th to 20th	Day	10% 16% 30% 23% 15% 6%	360
	21st to end	Day	7% 10% 29% 33% 18% 4	396
November	1st to 10th	Day	8% 10% 27% 34% 15% 6%	251
	11th to 20th	Day	4 12% 17% 34% 23% 9%	180
	21st to end	Day	3 11% 31% 23% 20% 12%	149
December	1st to 10th	Day	3 10% 21% 31% 22% 12%	90
	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% 31% 21% 5%	829
	21st to end	Night	3 8% 32% 31% 19% 7%	880
February	1st to 10th	Night	3 8% 25% 39% 23% 3	800
	11th to 20th	Night	2 10% 33% 32% 17% 5%	784
	21st to end	Night	2 7% 27% 40% 19% 5%	658
March	1st to 10th	Night	2 7% 29% 30% 24% 8%	774
	11th to 20th	Night	4 7% 24% 33% 21% 10%	551
	21st to end	Night	2 7% 25% 30% 28% 9%	594
April	1st to 10th	Night	4 7% 20% 34% 30% 6%	540
	11th to 20th	Night	6% 5% 23% 30% 29% 7%	533
	21st to end	Night	7% 5% 21% 31% 29% 7%	540
May	1st to 10th	Night	5% 7% 28% 30% 26% 4	440
	11th to 20th	Night	11% 9% 24% 27% 27% 2	339
	21st to end	Night	9% 5% 18% 30% 31% 8%	195
June	1st to 10th	Night	15% 3 21% 31% 27% 3	180
	11th to 20th	Night	17% 6% 18% 33% 26% 1	180
	21st to end	Night	16% 5% 17% 33% 27% 2	180
July	1st to 10th	Night	17% 2 19% 33% 28% 1	175
	11th to 20th	Night	20% 7% 17% 25% 26% 5%	174
	21st to end	Night	17% 5% 15% 31% 25% 6%	261
August	1st to 10th	Night	12% 7% 20% 31% 24% 5%	483
	11th to 20th	Night	16% 8% 22% 27% 20% 6%	534
	21st to end	Night	18% 7% 18% 31% 21% 4	594
September	1st to 10th	Night	19% 11% 22% 27% 17% 4	540
	11th to 20th	Night	11% 8% 23% 32% 22% 4	540
	21st to end	Night	16% 16% 23% 26% 14% 5%	621
October	1st to 10th	Night	12% 14% 28% 28% 14% 4	720
	11th to 20th	Night	12% 10% 24% 30% 19% 6%	780
	21st to end	Night	6% 7% 27% 35% 19% 5%	891
November	1st to 10th	Night	5% 8% 27% 35% 19% 7%	830
	11th to 20th	Night	4 8% 26% 32% 22% 7%	850
	21st to end	Night	5% 12% 29% 26% 20% 9%	850
December	1st to 10th	Night	3 10% 26% 33% 22% 6%	1030
	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 2024-01-13 06:37:59. Version ac07

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