Akulivik
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Akulivik 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	14% 13% 6% 11% 9% 5% 6% 6% 6% 6% 18%	74369
	Night	11% 14% 7% 13% 11% 7% 8% 7% 7% 5% 10%	75453
Transparency	Day	65% 6% 11% 14% 3	74010
	Night	71% 7% 8% 10% 3	75347
Seeing	Day	19% 5% 16% 27% 23% 10%	15953
	Night	17% 5% 16% 28% 26% 10%	23908

By Month

Percentage Cloud Cover NE (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	5% 8% 6% 11% 18% 8% 11% 9% 11% 4 9%	949
	11th to 20th	Day	4 9% 4 9% 15% 11% 15% 12% 14% 5% 3	925
	21st to end	Day	3 9% 5% 11% 12% 9% 13% 11% 14% 8% 6%	1254
February	1st to 10th	Day	2 6% 6% 13% 12% 7% 11% 13% 16% 9% 5%	1260
	11th to 20th	Day	2 6% 5% 12% 10% 6% 12% 13% 16% 9% 9%	1394
	21st to end	Day	2 6% 3 9% 12% 7% 11% 15% 17% 11% 8%	1332
March	1st to 10th	Day	5% 10% 5% 10% 13% 8% 11% 10% 14% 8% 7%	1689
	11th to 20th	Day	4 8% 5% 11% 11% 7% 10% 16% 12% 5% 12%	1969
	21st to end	Day	3 9% 5% 10% 10% 7% 11% 15% 9% 7% 15%	2278
April	1st to 10th	Day	6% 10% 4 8% 10% 6% 10% 9% 8% 6% 22%	2281
	11th to 20th	Day	5% 8% 6% 13% 15% 8% 10% 8% 5% 5% 16%	2420
	21st to end	Day	12% 12% 5% 12% 13% 7% 9% 6% 5% 5% 13%	2559
May	1st to 10th	Day	15% 14% 8% 15% 10% 5% 5% 4 4 5% 15%	2794
	11th to 20th	Day	12% 12% 7% 16% 10% 5% 5% 5% 5% 7% 17%	2833
	21st to end	Day	14% 13% 8% 14% 8% 3 5% 4 5% 6% 19%	3268
June	1st to 10th	Day	11% 13% 7% 10% 7% 4 5% 5% 5% 6% 27%	3219
	11th to 20th	Day	15% 9% 4 6% 5% 3 6% 4 5% 8% 34%	3240
	21st to end	Day	14% 9% 4 8% 5% 4 5% 6% 6% 9% 31%	3240
July	1st to 10th	Day	18% 10% 4 7% 6% 3 5% 5% 5% 7% 30%	3156
	11th to 20th	Day	18% 11% 5% 7% 5% 3 5% 5% 5% 7% 30%	3060
	21st to end	Day	17% 11% 4 7% 7% 4 5% 5% 5% 6% 28%	3225
August	1st to 10th	Day	22% 11% 3 7% 5% 3 4 5% 6% 8% 26%	2738
	11th to 20th	Day	27% 11% 3 6% 4 3 3 4 5% 5% 27%	2599
	21st to end	Day	28% 15% 5% 8% 5% 2 4 4 5% 6% 19%	2703
September	1st to 10th	Day	26% 14% 5% 9% 7% 3 5% 5% 4 5% 17%	2244
	11th to 20th	Day	24% 26% 6% 10% 8% 3 4 4 3 4 9%	2160
	21st to end	Day	27% 26% 6% 11% 6% 3 3 3 3 3 8%	1883
October	1st to 10th	Day	25% 27% 7% 9% 7% 3 3 3 3 3 9%	1800
	11th to 20th	Day	22% 26% 9% 11% 7% 3 3 3 2 2 12%	1585
	21st to end	Day	18% 24% 11% 11% 8% 3 4 4 4 3 9%	1584
November	1st to 10th	Day	11% 20% 12% 20% 11% 4 4 4 3 4 7%	1283
	11th to 20th	Day	14% 20% 12% 22% 11% 4 4 3 2 1 6%	1140
	21st to end	Day	8% 17% 10% 22% 16% 6% 7% 5% 3 3 4	1131
December	1st to 10th	Day	7% 12% 10% 21% 18% 7% 8% 7% 4 4 4	779
	11th to 20th	Day	6% 10% 6% 13% 19% 14% 11% 7% 4 4 5%	960
	21st to end	Day	6% 10% 6% 14% 25% 8% 8% 13% 4 2 4	1435
January	1st to 10th	Night	4 8% 6% 13% 16% 7% 9% 13% 9% 6% 9%	3216
	11th to 20th	Night	2 9% 5% 10% 12% 8% 16% 16% 13% 5% 3	3158
	21st to end	Night	3 8% 6% 12% 11% 6% 12% 14% 14% 7% 6%	3098
February	1st to 10th	Night	3 7% 7% 12% 10% 8% 12% 16% 15% 6% 4	2700
	11th to 20th	Night	2 7% 5% 9% 13% 9% 11% 14% 14% 9% 7%	2453
	21st to end	Night	2 7% 3 8% 13% 9% 13% 13% 17% 8% 7%	1924
March	1st to 10th	Night	5% 10% 5% 12% 14% 8% 11% 9% 14% 7% 6%	2258
	11th to 20th	Night	5% 10% 4 12% 10% 6% 10% 12% 13% 8% 10%	1989
	21st to end	Night	4 10% 4 10% 11% 7% 10% 12% 10% 7% 14%	2078
April	1st to 10th	Night	7% 12% 5% 9% 7% 6% 10% 9% 8% 8% 19%	1695
	11th to 20th	Night	6% 7% 6% 13% 15% 9% 10% 6% 5% 8% 17%	1488
	21st to end	Night	10% 15% 7% 12% 11% 7% 8% 5% 5% 6% 15%	1400
May	1st to 10th	Night	14% 17% 8% 14% 10% 5% 4 4 3 5% 16%	1165
	11th to 20th	Night	12% 14% 10% 16% 9% 4 3 3 3 4 20%	1062
	21st to end	Night	16% 14% 11% 15% 6% 3 3 3 6% 5% 17%	1005
June	1st to 10th	Night	11% 11% 10% 14% 4 3 4 5% 6% 6% 28%	738
	11th to 20th	Night	15% 12% 4 6% 5% 4 3 5% 5% 5% 36%	720
	21st to end	Night	12% 9% 5% 9% 5% 4 5% 5% 7% 7% 32%	720
July	1st to 10th	Night	18% 10% 7% 8% 4 4 4 3 5% 6% 30%	801
	11th to 20th	Night	22% 11% 4 8% 6% 4 5% 4 5% 5% 25%	900
	21st to end	Night	19% 12% 5% 8% 6% 3 3 4 6% 6% 28%	1093
August	1st to 10th	Night	23% 12% 4 6% 6% 3 5% 5% 5% 7% 24%	1199
	11th to 20th	Night	26% 11% 3 6% 4 2 3 4 5% 7% 29%	1302
	21st to end	Night	26% 16% 4 7% 5% 4 4 4 4 5% 21%	1651
September	1st to 10th	Night	27% 17% 5% 9% 6% 3 4 5% 4 4 16%	1698
	11th to 20th	Night	25% 26% 7% 13% 7% 4 3 3 3 3 7%	1800
	21st to end	Night	29% 27% 6% 9% 6% 3 3 3 2 2 10%	2074
October	1st to 10th	Night	25% 30% 7% 8% 6% 3 3 3 3 2 11%	2160
	11th to 20th	Night	20% 26% 10% 12% 6% 3 3 3 3 3 12%	2372
	21st to end	Night	19% 25% 13% 12% 7% 4 4 3 4 3 6%	2772
November	1st to 10th	Night	12% 21% 11% 20% 9% 5% 5% 4 4 3 6%	2795
	11th to 20th	Night	13% 21% 12% 21% 11% 5% 4 3 2 2 6%	3040
	21st to end	Night	8% 16% 11% 22% 16% 7% 7% 3 3 3 4	3047
December	1st to 10th	Night	6% 13% 9% 20% 19% 9% 9% 6% 3 2 4	3401
	11th to 20th	Night	6% 12% 6% 18% 19% 15% 8% 6% 3 2 4	4242
	21st to end	Night	6% 13% 7% 16% 19% 9% 10% 8% 5% 3 4	6239

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% 10% 9% 14% 2	950
	11th to 20th	Day	69% 10% 10% 9% 3	925
	21st to end	Day	62% 9% 7% 13% 9%	1254
February	1st to 10th	Day	58% 11% 12% 15% 4	1260
	11th to 20th	Day	55% 8% 15% 16% 6%	1401
	21st to end	Day	53% 9% 10% 17% 11%	1332
March	1st to 10th	Day	64% 6% 9% 15% 6%	1692
	11th to 20th	Day	58% 9% 10% 16% 6%	1969
	21st to end	Day	59% 9% 9% 16% 7%	2278
April	1st to 10th	Day	57% 6% 9% 18% 9% 1	2281
	11th to 20th	Day	69% 6% 7% 13% 4 1	2420
	21st to end	Day	73% 6% 7% 11% 2	2559
May	1st to 10th	Day	75% 3 8% 12% 3	2794
	11th to 20th	Day	69% 5% 10% 12% 4	2837
	21st to end	Day	68% 4 11% 14% 3	3268
June	1st to 10th	Day	58% 5% 12% 20% 5%	3219
	11th to 20th	Day	49% 6% 14% 25% 6%	3240
	21st to end	Day	50% 6% 16% 25% 4	3240
July	1st to 10th	Day	51% 6% 15% 23% 4	3071
	11th to 20th	Day	53% 7% 18% 19% 2	2967
	21st to end	Day	55% 7% 16% 17% 4	3046
August	1st to 10th	Day	56% 10% 20% 12% 2	2721
	11th to 20th	Day	58% 6% 16% 16% 3	2599
	21st to end	Day	67% 6% 14% 13% 1	2703
September	1st to 10th	Day	71% 6% 11% 11% 1	2244
	11th to 20th	Day	80% 5% 8% 6%	2160
	21st to end	Day	83% 4 9% 4 1	1883
October	1st to 10th	Day	81% 5% 7% 6% 1	1800
	11th to 20th	Day	80% 4 6% 7% 2	1585
	21st to end	Day	79% 5% 8% 8% 1	1584
November	1st to 10th	Day	80% 9% 5% 5% 1	1283
	11th to 20th	Day	86% 4 6% 3	1140
	21st to end	Day	82% 8% 4 6%	1131
December	1st to 10th	Day	79% 8% 8% 5% 1	779
	11th to 20th	Day	79% 8% 7% 5% 1	960
	21st to end	Day	79% 8% 7% 5% 2	1435
January	1st to 10th	Night	64% 11% 8% 15% 3	3216
	11th to 20th	Night	64% 12% 11% 11% 2	3158
	21st to end	Night	61% 9% 10% 12% 8%	3098
February	1st to 10th	Night	63% 10% 10% 14% 4	2700
	11th to 20th	Night	60% 9% 11% 15% 5%	2456
	21st to end	Night	57% 7% 12% 13% 11%	1924
March	1st to 10th	Night	65% 6% 8% 14% 6%	2268
	11th to 20th	Night	58% 7% 11% 17% 6%	1990
	21st to end	Night	60% 8% 10% 14% 7%	2078
April	1st to 10th	Night	57% 6% 9% 18% 9% 1	1695
	11th to 20th	Night	65% 6% 7% 16% 6%	1488
	21st to end	Night	70% 5% 6% 15% 3	1400
May	1st to 10th	Night	74% 4 6% 13% 3	1165
	11th to 20th	Night	70% 3 7% 16% 4	1063
	21st to end	Night	69% 4 9% 12% 5%	1006
June	1st to 10th	Night	56% 5% 13% 19% 6% 1	738
	11th to 20th	Night	49% 6% 10% 26% 9%	720
	21st to end	Night	53% 5% 12% 25% 5%	720
July	1st to 10th	Night	54% 5% 13% 23% 5%	777
	11th to 20th	Night	58% 7% 18% 15% 2	870
	21st to end	Night	56% 6% 19% 17% 3	1032
August	1st to 10th	Night	61% 8% 18% 11% 2	1192
	11th to 20th	Night	56% 6% 17% 18% 3	1302
	21st to end	Night	65% 6% 14% 12% 2	1651
September	1st to 10th	Night	71% 6% 11% 9% 2	1698
	11th to 20th	Night	82% 6% 6% 6%	1800
	21st to end	Night	81% 5% 8% 6% 1	2074
October	1st to 10th	Night	80% 5% 6% 7% 2	2160
	11th to 20th	Night	79% 5% 7% 8% 2	2372
	21st to end	Night	82% 6% 6% 5% 1	2772
November	1st to 10th	Night	80% 8% 5% 5% 1	2795
	11th to 20th	Night	85% 6% 5% 4 1	3040
	21st to end	Night	82% 8% 5% 4	3047
December	1st to 10th	Night	83% 9% 4 3 1	3401
	11th to 20th	Night	83% 7% 5% 4 1	4242
	21st to end	Night	80% 8% 5% 5% 1	6239

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 9% 40% 36% 11%	180
	11th to 20th	Day	9% 3 17% 38% 19% 14%	170
	21st to end	Day	5% 1 16% 28% 36% 14%	176
February	1st to 10th	Day	3 3 9% 30% 32% 23%	160
	11th to 20th	Day	2 9% 28% 42% 18%	190
	21st to end	Day	2 2 10% 31% 34% 22%	198
March	1st to 10th	Day	9% 4 17% 23% 27% 20%	312
	11th to 20th	Day	6% 4 17% 29% 28% 17%	420
	21st to end	Day	8% 3 20% 29% 25% 14%	462
April	1st to 10th	Day	9% 1 12% 32% 29% 18%	420
	11th to 20th	Day	7% 3 13% 32% 26% 20%	412
	21st to end	Day	15% 7% 26% 25% 17% 9%	459
May	1st to 10th	Day	20% 5% 22% 27% 17% 10%	697
	11th to 20th	Day	19% 5% 20% 27% 20% 9%	802
	21st to end	Day	19% 5% 19% 27% 21% 9%	874
June	1st to 10th	Day	15% 3 20% 33% 20% 9%	810
	11th to 20th	Day	19% 4 12% 31% 24% 10%	810
	21st to end	Day	18% 3 17% 27% 24% 10%	810
July	1st to 10th	Day	22% 4 12% 27% 25% 10%	796
	11th to 20th	Day	24% 4 15% 26% 24% 8%	792
	21st to end	Day	22% 5% 9% 25% 27% 11%	881
August	1st to 10th	Day	27% 4 13% 22% 24% 11%	678
	11th to 20th	Day	29% 4 11% 24% 21% 11%	557
	21st to end	Day	40% 3 14% 18% 18% 7%	495
September	1st to 10th	Day	29% 6% 16% 25% 15% 8%	450
	11th to 20th	Day	32% 8% 18% 22% 15% 4	450
	21st to end	Day	38% 9% 19% 18% 13% 3	450
October	1st to 10th	Day	36% 10% 22% 22% 8% 2	450
	11th to 20th	Day	26% 5% 19% 27% 20% 4	296
	21st to end	Day	20% 9% 18% 26% 22% 6%	198
November	1st to 10th	Day	10% 6% 22% 29% 16% 17%	180
	11th to 20th	Day	15% 6% 17% 26% 28% 8%	180
	21st to end	Day	9% 7% 21% 24% 27% 12%	180
December	1st to 10th	Day	10% 4 20% 32% 22% 12%	180
	11th to 20th	Day	11% 6% 18% 29% 25% 11%	180
	21st to end	Day	6% 6% 19% 34% 27% 9%	198
January	1st to 10th	Night	7% 3 11% 32% 32% 15%	1040
	11th to 20th	Night	6% 2 15% 31% 30% 16%	1015
	21st to end	Night	5% 2 11% 27% 35% 19%	1034
February	1st to 10th	Night	6% 3 11% 25% 36% 19%	900
	11th to 20th	Night	4 1 9% 30% 39% 18%	776
	21st to end	Night	3 2 13% 26% 39% 18%	592
March	1st to 10th	Night	7% 3 14% 26% 31% 18%	720
	11th to 20th	Night	8% 4 19% 32% 26% 11%	720
	21st to end	Night	7% 4 19% 29% 31% 10%	792
April	1st to 10th	Night	11% 2 18% 30% 27% 12%	615
	11th to 20th	Night	8% 3 13% 33% 32% 12%	424
	21st to end	Night	16% 8% 19% 29% 19% 9%	360
May	1st to 10th	Night	20% 5% 21% 29% 19% 6%	360
	11th to 20th	Night	18% 6% 16% 34% 21% 6%	354
	21st to end	Night	22% 4 17% 29% 21% 6%	389
June	1st to 10th	Night	16% 3 20% 37% 19% 5%	360
	11th to 20th	Night	21% 4 13% 35% 23% 4	360
	21st to end	Night	17% 4 18% 26% 29% 5%	360
July	1st to 10th	Night	24% 2 11% 33% 24% 6%	350
	11th to 20th	Night	28% 4 8% 28% 27% 5%	348
	21st to end	Night	25% 3 11% 28% 27% 5%	394
August	1st to 10th	Night	28% 4 9% 23% 28% 7%	358
	11th to 20th	Night	31% 3 15% 18% 27% 6%	356
	21st to end	Night	36% 4 13% 21% 22% 4	463
September	1st to 10th	Night	35% 5% 17% 22% 16% 4	618
	11th to 20th	Night	38% 9% 15% 19% 15% 3	720
	21st to end	Night	42% 9% 18% 16% 12% 4	720
October	1st to 10th	Night	40% 9% 17% 22% 11% 1	720
	11th to 20th	Night	32% 6% 19% 25% 15% 3	720
	21st to end	Night	29% 7% 17% 24% 17% 7%	792
November	1st to 10th	Night	18% 6% 19% 27% 21% 9%	874
	11th to 20th	Night	18% 7% 20% 28% 21% 6%	1040
	21st to end	Night	11% 7% 16% 30% 28% 8%	1040
December	1st to 10th	Night	10% 3 18% 32% 26% 10%	1040
	11th to 20th	Night	11% 5% 18% 29% 25% 12%	1040
	21st to end	Night	10% 4 16% 29% 28% 12%	1144

Page generated at 2024-01-13 09:37:58. Version ac07

Copyright 2024 Attilla Danko