Iqaluit
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Iqaluit clear sky chart from 2005-11-06 to 2025-03-27.

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% 5% 11% 7% 6% 6% 5% 6% 7% 21%	107368
	Night	8% 12% 5% 13% 8% 8% 7% 6% 7% 8% 18%	112211
Transparency	Day	61% 7% 14% 14% 4	110305
	Night	59% 7% 14% 14% 5%	117455
Seeing	Day	20% 6% 18% 25% 20% 11%	17649
	Night	14% 5% 16% 29% 27% 10%	24549

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	7% 17% 4 11% 8% 6% 7% 6% 6% 9% 19%	1534
	11th to 20th	Day	4 14% 6% 19% 14% 11% 6% 5% 5% 6% 10%	1972
	21st to end	Day	1 4 3 11% 9% 10% 14% 11% 11% 12% 14%	2711
February	1st to 10th	Day	8% 4 12% 9% 10% 12% 8% 10% 9% 17%	1271
	11th to 20th	Day	2 5% 4 10% 6% 7% 10% 10% 12% 11% 24%	1491
	21st to end	Day	3 6% 3 9% 8% 11% 11% 8% 11% 10% 20%	1395
March	1st to 10th	Day	1 4 3 9% 6% 7% 11% 9% 12% 10% 29%	3079
	11th to 20th	Day	3 11% 4 10% 6% 8% 8% 8% 9% 9% 25%	3476
	21st to end	Day	7% 12% 6% 13% 8% 6% 6% 5% 5% 8% 26%	4104
April	1st to 10th	Day	6% 14% 5% 11% 8% 6% 6% 5% 5% 7% 27%	2470
	11th to 20th	Day	6% 10% 5% 11% 10% 9% 7% 5% 6% 7% 25%	2597
	21st to end	Day	11% 18% 5% 14% 10% 7% 5% 3 5% 6% 17%	2850
May	1st to 10th	Day	8% 12% 5% 16% 13% 6% 4 3 4 6% 21%	5050
	11th to 20th	Day	10% 14% 5% 12% 7% 5% 5% 3 4 5% 30%	5340
	21st to end	Day	8% 16% 8% 21% 8% 6% 6% 4 6% 6% 11%	6221
June	1st to 10th	Day	19% 13% 7% 12% 8% 5% 4 4 5% 6% 18%	3610
	11th to 20th	Day	15% 14% 5% 9% 6% 6% 6% 4 7% 7% 22%	3610
	21st to end	Day	22% 17% 5% 10% 6% 5% 4 4 5% 5% 17%	3610
July	1st to 10th	Day	28% 12% 3 8% 5% 4 5% 4 5% 6% 18%	6010
	11th to 20th	Day	26% 12% 4 7% 5% 5% 4 3 5% 6% 23%	5793
	21st to end	Day	17% 9% 3 8% 5% 5% 5% 5% 7% 8% 28%	5865
August	1st to 10th	Day	22% 11% 4 9% 5% 5% 5% 4 5% 7% 21%	5120
	11th to 20th	Day	14% 8% 3 8% 5% 5% 4 4 5% 7% 36%	4674
	21st to end	Day	28% 12% 4 9% 4 4 3 3 5% 6% 21%	4834
September	1st to 10th	Day	22% 14% 5% 10% 6% 4 4 3 4 5% 22%	2470
	11th to 20th	Day	20% 19% 6% 12% 6% 5% 4 3 4 6% 14%	2208
	21st to end	Day	23% 21% 5% 11% 4 4 5% 3 4 4 15%	2086
October	1st to 10th	Day	21% 21% 8% 10% 4 3 4 3 5% 5% 17%	1798
	11th to 20th	Day	14% 18% 7% 13% 6% 5% 4 3 5% 6% 18%	1658
	21st to end	Day	11% 19% 8% 14% 6% 5% 6% 3 5% 7% 17%	1552
November	1st to 10th	Day	5% 11% 5% 18% 10% 8% 6% 5% 8% 9% 17%	1259
	11th to 20th	Day	11% 17% 6% 15% 9% 6% 5% 5% 6% 7% 13%	1045
	21st to end	Day	9% 18% 7% 16% 7% 7% 5% 5% 6% 7% 13%	910
December	1st to 10th	Day	2 8% 4 16% 10% 7% 7% 5% 9% 13% 20%	1037
	11th to 20th	Day	2 11% 2 11% 10% 9% 9% 8% 9% 10% 18%	1140
	21st to end	Day	2 10% 7% 15% 9% 9% 7% 7% 6% 11% 17%	1518
January	1st to 10th	Night	5% 15% 6% 11% 8% 8% 8% 6% 8% 9% 16%	8437
	11th to 20th	Night	4 12% 7% 19% 13% 10% 8% 5% 6% 6% 11%	7953
	21st to end	Night	1 4 3 13% 10% 12% 13% 9% 11% 10% 15%	8276
February	1st to 10th	Night	1 7% 4 12% 10% 10% 11% 9% 10% 9% 17%	3129
	11th to 20th	Night	2 5% 3 9% 8% 8% 9% 7% 11% 10% 27%	2792
	21st to end	Night	2 8% 3 10% 9% 7% 13% 8% 10% 10% 20%	2235
March	1st to 10th	Night	3 6% 2 7% 7% 7% 12% 10% 12% 9% 25%	3978
	11th to 20th	Night	2 11% 3 11% 8% 8% 10% 7% 9% 9% 22%	3703
	21st to end	Night	5% 12% 6% 15% 8% 9% 8% 5% 6% 5% 21%	3666
April	1st to 10th	Night	8% 15% 5% 12% 8% 6% 5% 4 6% 4 27%	1710
	11th to 20th	Night	4 12% 4 14% 11% 9% 7% 6% 6% 6% 20%	1550
	21st to end	Night	11% 19% 5% 15% 9% 7% 5% 3 5% 4 18%	1330
May	1st to 10th	Night	8% 13% 5% 20% 12% 6% 5% 4 5% 5% 18%	1902
	11th to 20th	Night	10% 17% 5% 12% 7% 4 5% 3 4 6% 27%	1575
	21st to end	Night	7% 19% 12% 19% 8% 6% 4 4 6% 5% 10%	1369
June	1st to 10th	Night	21% 17% 5% 11% 5% 4 4 4 6% 5% 18%	570
	11th to 20th	Night	13% 15% 4 9% 8% 5% 5% 4 4 8% 25%	570
	21st to end	Night	26% 16% 4 9% 4 5% 2 4 4 4 21%	570
July	1st to 10th	Night	33% 14% 4 9% 4 5% 4 3 5% 4 16%	960
	11th to 20th	Night	26% 11% 3 10% 5% 4 4 2 5% 6% 24%	1182
	21st to end	Night	22% 8% 2 8% 5% 4 4 4 6% 8% 28%	1697
August	1st to 10th	Night	25% 12% 3 9% 6% 4 5% 3 4 5% 25%	1816
	11th to 20th	Night	17% 7% 3 7% 4 4 5% 5% 6% 8% 36%	2165
	21st to end	Night	31% 10% 3 8% 4 5% 4 4 5% 6% 19%	2791
September	1st to 10th	Night	22% 12% 4 8% 5% 5% 4 3 5% 7% 25%	1710
	11th to 20th	Night	20% 18% 6% 12% 6% 6% 4 4 4 4 15%	1971
	21st to end	Night	24% 20% 6% 11% 6% 4 4 4 4 4 14%	2094
October	1st to 10th	Night	20% 23% 6% 12% 5% 4 4 3 4 4 13%	2380
	11th to 20th	Night	15% 17% 8% 13% 6% 5% 5% 3 4 6% 17%	2522
	21st to end	Night	11% 20% 7% 16% 6% 6% 4 3 5% 7% 15%	3045
November	1st to 10th	Night	6% 14% 6% 15% 9% 8% 6% 6% 7% 9% 16%	3038
	11th to 20th	Night	10% 19% 8% 15% 8% 6% 5% 4 6% 6% 12%	3353
	21st to end	Night	8% 18% 6% 14% 10% 7% 6% 5% 6% 8% 12%	3489
December	1st to 10th	Night	2 8% 5% 17% 11% 8% 7% 6% 10% 11% 17%	6153
	11th to 20th	Night	4 10% 4 14% 9% 9% 8% 6% 8% 8% 19%	7070
	21st to end	Night	2 11% 7% 13% 8% 9% 8% 5% 7% 9% 21%	9460

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	56% 10% 12% 14% 8% 1	1535
	11th to 20th	Day	73% 7% 11% 8% 1	1989
	21st to end	Day	51% 8% 17% 14% 10%	2711
February	1st to 10th	Day	53% 10% 19% 14% 4	1271
	11th to 20th	Day	42% 9% 19% 23% 7%	1498
	21st to end	Day	48% 9% 14% 18% 8% 2	1395
March	1st to 10th	Day	37% 9% 16% 22% 15%	3082
	11th to 20th	Day	49% 6% 16% 17% 12%	3476
	21st to end	Day	57% 4 10% 20% 8%	4104
April	1st to 10th	Day	54% 6% 11% 17% 12% 1	2470
	11th to 20th	Day	58% 5% 10% 18% 8% 1	2597
	21st to end	Day	69% 4 9% 14% 3	2850
May	1st to 10th	Day	63% 8% 12% 14% 3	5065
	11th to 20th	Day	54% 8% 9% 18% 10%	5344
	21st to end	Day	74% 7% 11% 7% 2	6221
June	1st to 10th	Day	68% 5% 12% 13% 2	3610
	11th to 20th	Day	60% 8% 14% 16% 3	3610
	21st to end	Day	68% 6% 13% 11% 3	3610
July	1st to 10th	Day	67% 6% 17% 9% 2	5916
	11th to 20th	Day	62% 6% 16% 14% 1	5691
	21st to end	Day	52% 7% 23% 15% 2	5679
August	1st to 10th	Day	61% 7% 16% 14% 2	5102
	11th to 20th	Day	47% 6% 15% 24% 7%	4719
	21st to end	Day	66% 6% 14% 13% 2	4834
September	1st to 10th	Day	66% 5% 13% 14% 2	2470
	11th to 20th	Day	73% 5% 13% 8% 1	2208
	21st to end	Day	72% 6% 9% 10% 2	2086
October	1st to 10th	Day	76% 4 10% 8% 2	2980
	11th to 20th	Day	69% 5% 9% 16% 1	2736
	21st to end	Day	67% 7% 12% 12% 2	2537
November	1st to 10th	Day	60% 8% 16% 13% 4	1259
	11th to 20th	Day	67% 8% 14% 10% 1	1045
	21st to end	Day	67% 8% 11% 12% 3	910
December	1st to 10th	Day	54% 9% 21% 14% 3	1037
	11th to 20th	Day	50% 9% 15% 22% 4	1140
	21st to end	Day	56% 6% 9% 18% 10% 1	1518
January	1st to 10th	Night	57% 9% 14% 12% 8% 1	8437
	11th to 20th	Night	71% 6% 12% 9% 1	8011
	21st to end	Night	54% 7% 14% 15% 10%	8276
February	1st to 10th	Night	53% 11% 17% 14% 5%	3129
	11th to 20th	Night	44% 9% 21% 22% 5%	2796
	21st to end	Night	49% 8% 15% 19% 7% 2	2235
March	1st to 10th	Night	40% 9% 17% 19% 15%	3988
	11th to 20th	Night	50% 6% 13% 18% 13%	3704
	21st to end	Night	59% 8% 10% 13% 9%	3666
April	1st to 10th	Night	57% 5% 8% 19% 11% 1	1710
	11th to 20th	Night	60% 6% 9% 16% 9% 1	1550
	21st to end	Night	70% 4 8% 13% 4 1	1330
May	1st to 10th	Night	64% 7% 11% 15% 2	1907
	11th to 20th	Night	56% 8% 9% 17% 10%	1576
	21st to end	Night	73% 7% 11% 6% 3	1370
June	1st to 10th	Night	66% 5% 11% 16% 2	570
	11th to 20th	Night	59% 6% 14% 18% 3	570
	21st to end	Night	69% 4 10% 13% 4	570
July	1st to 10th	Night	72% 5% 12% 10% 1	945
	11th to 20th	Night	62% 6% 19% 12% 1	1162
	21st to end	Night	51% 7% 23% 15% 5%	1643
August	1st to 10th	Night	62% 6% 15% 17% 1	1810
	11th to 20th	Night	46% 7% 17% 27% 3	2186
	21st to end	Night	66% 6% 15% 12% 1	2791
September	1st to 10th	Night	58% 7% 19% 15% 1	1710
	11th to 20th	Night	71% 6% 13% 9% 1	1971
	21st to end	Night	73% 6% 8% 11% 1	2094
October	1st to 10th	Night	79% 4 9% 7% 2	3978
	11th to 20th	Night	70% 6% 11% 11% 2	4186
	21st to end	Night	65% 7% 11% 14% 2	5021
November	1st to 10th	Night	59% 10% 16% 11% 4	3038
	11th to 20th	Night	69% 7% 13% 9% 2	3353
	21st to end	Night	67% 6% 12% 12% 2	3489
December	1st to 10th	Night	56% 9% 22% 11% 3	6153
	11th to 20th	Night	53% 8% 14% 22% 3	7070
	21st to end	Night	54% 7% 10% 20% 7% 2	9460

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	5% 5% 13% 34% 32% 12%	133
	11th to 20th	Day	7% 5% 14% 31% 30% 14%	200
	21st to end	Day	5% 6% 16% 28% 27% 19%	220
February	1st to 10th	Day	1 4 16% 27% 30% 24%	200
	11th to 20th	Day	2 3 14% 27% 32% 24%	200
	21st to end	Day	3 3 18% 28% 28% 20%	241
March	1st to 10th	Day	5% 5% 16% 29% 30% 15%	457
	11th to 20th	Day	5% 3 18% 26% 33% 16%	500
	21st to end	Day	6% 6% 18% 30% 23% 18%	530
April	1st to 10th	Day	11% 8% 23% 26% 22% 10%	460
	11th to 20th	Day	9% 5% 17% 26% 27% 15%	502
	21st to end	Day	16% 11% 23% 26% 14% 9%	650
May	1st to 10th	Day	17% 6% 19% 25% 23% 10%	743
	11th to 20th	Day	19% 6% 20% 25% 18% 11%	862
	21st to end	Day	17% 6% 18% 27% 21% 11%	940
June	1st to 10th	Day	23% 7% 15% 24% 20% 11%	870
	11th to 20th	Day	19% 7% 18% 26% 20% 10%	870
	21st to end	Day	31% 7% 19% 22% 15% 6%	870
July	1st to 10th	Day	29% 6% 17% 21% 18% 10%	856
	11th to 20th	Day	31% 6% 16% 21% 18% 7%	852
	21st to end	Day	23% 6% 16% 24% 20% 11%	947
August	1st to 10th	Day	24% 5% 16% 27% 17% 11%	857
	11th to 20th	Day	27% 7% 19% 20% 18% 9%	667
	21st to end	Day	31% 9% 19% 21% 12% 8%	601
September	1st to 10th	Day	27% 6% 20% 23% 17% 8%	490
	11th to 20th	Day	28% 6% 17% 22% 16% 11%	490
	21st to end	Day	29% 6% 20% 27% 14% 5%	487
October	1st to 10th	Day	27% 10% 17% 23% 19% 4	390
	11th to 20th	Day	22% 6% 18% 23% 21% 11%	390
	21st to end	Day	17% 8% 21% 24% 17% 14%	309
November	1st to 10th	Day	6% 5% 15% 31% 26% 18%	200
	11th to 20th	Day	10% 4 14% 32% 29% 12%	200
	21st to end	Day	14% 6% 22% 30% 18% 10%	155
December	1st to 10th	Day	5% 4 19% 39% 22% 11%	100
	11th to 20th	Day	7% 8% 22% 27% 28% 8%	100
	21st to end	Day	5% 4 23% 32% 28% 8%	110
January	1st to 10th	Night	6% 3 13% 25% 36% 18%	1100
	11th to 20th	Night	5% 4 13% 26% 35% 18%	1100
	21st to end	Night	5% 5% 15% 31% 30% 15%	1210
February	1st to 10th	Night	3 3 15% 29% 36% 14%	1029
	11th to 20th	Night	4 1 12% 27% 38% 17%	816
	21st to end	Night	4 3 13% 35% 33% 12%	660
March	1st to 10th	Night	4 4 14% 31% 35% 11%	800
	11th to 20th	Night	7% 3 20% 30% 29% 11%	800
	21st to end	Night	7% 5% 15% 28% 32% 13%	861
April	1st to 10th	Night	13% 6% 21% 37% 18% 5%	570
	11th to 20th	Night	8% 4 17% 34% 30% 8%	476
	21st to end	Night	18% 8% 20% 27% 21% 6%	380
May	1st to 10th	Night	19% 6% 17% 32% 22% 4	380
	11th to 20th	Night	20% 3 18% 34% 19% 7%	374
	21st to end	Night	13% 5% 18% 31% 25% 7%	311
June	1st to 10th	Night	29% 4 13% 26% 26% 2	190
	11th to 20th	Night	17% 7% 19% 31% 23% 3	190
	21st to end	Night	29% 8% 15% 32% 15% 1	190
July	1st to 10th	Night	31% 4 10% 27% 26% 2	185
	11th to 20th	Night	29% 5% 12% 24% 25% 4	313
	21st to end	Night	25% 4 11% 27% 28% 5%	416
August	1st to 10th	Night	23% 6% 13% 27% 26% 5%	378
	11th to 20th	Night	28% 4 13% 29% 21% 4	376
	21st to end	Night	32% 6% 13% 27% 18% 4	485
September	1st to 10th	Night	26% 6% 15% 27% 23% 3	570
	11th to 20th	Night	29% 4 17% 25% 21% 4	693
	21st to end	Night	32% 5% 17% 26% 17% 2	760
October	1st to 10th	Night	27% 8% 19% 27% 16% 3	760
	11th to 20th	Night	22% 7% 19% 28% 19% 5%	787
	21st to end	Night	18% 7% 20% 25% 20% 11%	946
November	1st to 10th	Night	10% 4 15% 32% 29% 10%	880
	11th to 20th	Night	17% 6% 16% 26% 27% 7%	1053
	21st to end	Night	14% 5% 17% 28% 24% 12%	1100
December	1st to 10th	Night	8% 3 15% 32% 30% 12%	1100
	11th to 20th	Night	8% 4 19% 29% 28% 12%	1100
	21st to end	Night	6% 4 15% 31% 31% 14%	1210

Page generated at 2025-03-24 09:04:27. Version ac07

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