Kitimat
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kitimat clear sky chart from 2005-11-06 to 2026-06-01.

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	25% 16% 4 9% 5% 4 4 3 4 5% 19%	136919
	Night	27% 20% 5% 9% 5% 4 3 3 3 4 18%	134928
Transparency	Day	66% 8% 10% 11% 4	136613
	Night	70% 6% 9% 10% 4 1	134812
Seeing	Day	35% 17% 21% 18% 8% 1	18187
	Night	39% 13% 21% 18% 8% 1	25724

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	25% 25% 6% 9% 5% 4 4 3 3 3 13%	4125
	11th to 20th	Day	22% 18% 5% 8% 3 3 3 3 4 5% 27%	4119
	21st to end	Day	33% 20% 5% 9% 4 3 2 2 2 3 18%	4764
February	1st to 10th	Day	32% 17% 4 7% 4 3 2 3 3 4 21%	1680
	11th to 20th	Day	21% 22% 4 7% 3 4 3 2 5% 4 24%	1769
	21st to end	Day	19% 23% 3 7% 4 4 3 4 3 5% 24%	1609
March	1st to 10th	Day	17% 20% 5% 11% 6% 4 4 3 4 5% 20%	4596
	11th to 20th	Day	18% 23% 5% 11% 6% 6% 5% 4 5% 5% 12%	5052
	21st to end	Day	17% 18% 4 9% 4 4 5% 3 5% 6% 25%	5712
April	1st to 10th	Day	22% 24% 5% 11% 6% 5% 3 3 3 4 14%	2628
	11th to 20th	Day	22% 22% 4 9% 5% 4 4 3 4 6% 18%	2698
	21st to end	Day	24% 19% 4 8% 5% 4 3 3 4 5% 20%	2730
May	1st to 10th	Day	20% 16% 5% 11% 7% 6% 5% 4 5% 6% 15%	6872
	11th to 20th	Day	27% 15% 5% 9% 6% 5% 4 4 4 5% 17%	6886
	21st to end	Day	26% 19% 5% 13% 6% 5% 4 3 4 4 11%	7570
June	1st to 10th	Day	30% 13% 3 9% 5% 5% 5% 3 5% 5% 16%	3001
	11th to 20th	Day	31% 14% 5% 9% 6% 4 4 3 5% 6% 14%	3195
	21st to end	Day	33% 14% 4 9% 5% 4 4 4 4 4 16%	3200
July	1st to 10th	Day	18% 11% 4 8% 6% 5% 5% 4 7% 6% 27%	7158
	11th to 20th	Day	17% 10% 4 8% 5% 5% 5% 4 6% 7% 28%	6780
	21st to end	Day	19% 8% 3 8% 6% 5% 6% 4 6% 7% 28%	7375
August	1st to 10th	Day	14% 6% 2 6% 3 3 3 3 4 6% 49%	4692
	11th to 20th	Day	23% 13% 4 9% 5% 4 4 3 4 5% 28%	4320
	21st to end	Day	28% 12% 4 9% 4 5% 4 3 5% 6% 20%	4664
September	1st to 10th	Day	34% 11% 3 8% 5% 4 4 3 5% 5% 20%	2550
	11th to 20th	Day	31% 10% 3 8% 5% 5% 5% 4 4 5% 21%	2200
	21st to end	Day	45% 14% 4 9% 5% 3 3 2 3 3 10%	2200
October	1st to 10th	Day	34% 17% 7% 12% 5% 3 3 2 4 3 11%	3408
	11th to 20th	Day	36% 16% 4 11% 6% 5% 5% 4 4 3 7%	2948
	21st to end	Day	26% 16% 6% 11% 6% 4 3 2 3 4 19%	3170
November	1st to 10th	Day	41% 19% 4 7% 5% 3 3 2 3 3 10%	1648
	11th to 20th	Day	34% 24% 4 10% 4 5% 4 2 3 2 9%	1480
	21st to end	Day	33% 22% 4 8% 4 3 3 2 3 4 14%	1470
December	1st to 10th	Day	30% 25% 6% 7% 4 2 3 2 3 3 15%	2360
	11th to 20th	Day	30% 21% 6% 10% 5% 4 4 2 3 3 13%	2715
	21st to end	Day	29% 26% 6% 13% 6% 4 3 2 2 2 6%	3575
January	1st to 10th	Night	26% 24% 6% 11% 4 4 3 2 3 3 12%	8770
	11th to 20th	Night	24% 17% 4 7% 3 3 3 3 4 6% 26%	8779
	21st to end	Night	35% 20% 4 7% 3 3 2 2 3 4 17%	9424
February	1st to 10th	Night	32% 19% 4 6% 3 3 2 2 3 3 22%	2940
	11th to 20th	Night	23% 23% 5% 8% 4 3 3 2 3 5% 22%	2738
	21st to end	Night	16% 23% 5% 10% 5% 3 4 3 4 3 25%	2194
March	1st to 10th	Night	15% 20% 5% 11% 6% 5% 4 3 4 5% 21%	5498
	11th to 20th	Night	18% 25% 7% 13% 6% 5% 4 3 3 3 11%	5163
	21st to end	Night	15% 17% 5% 10% 6% 5% 5% 3 5% 5% 25%	5499
April	1st to 10th	Night	21% 23% 5% 11% 6% 4 4 3 4 3 16%	1991
	11th to 20th	Night	20% 20% 4 9% 6% 4 4 3 4 5% 21%	1871
	21st to end	Night	24% 20% 4 8% 4 3 4 3 4 5% 22%	1890
May	1st to 10th	Night	21% 22% 5% 11% 6% 5% 5% 4 4 4 14%	3306
	11th to 20th	Night	29% 16% 5% 11% 6% 5% 5% 4 4 4 11%	3229
	21st to end	Night	27% 21% 6% 11% 5% 4 4 3 3 3 13%	3547
June	1st to 10th	Night	32% 13% 4 8% 5% 4 3 3 4 4 21%	1400
	11th to 20th	Night	31% 17% 3 10% 6% 5% 4 4 4 4 14%	1200
	21st to end	Night	33% 14% 4 9% 5% 5% 4 3 2 4 18%	1200
July	1st to 10th	Night	23% 15% 5% 10% 4 3 3 2 3 4 30%	2799
	11th to 20th	Night	20% 12% 4 9% 5% 4 4 4 4 7% 28%	3180
	21st to end	Night	19% 10% 3 10% 5% 5% 4 4 5% 7% 27%	3468
August	1st to 10th	Night	14% 6% 2 6% 3 3 3 2 4 5% 51%	2462
	11th to 20th	Night	25% 11% 4 11% 6% 5% 4 3 4 5% 23%	2738
	21st to end	Night	28% 18% 5% 10% 5% 4 4 3 4 3 16%	3245
September	1st to 10th	Night	34% 11% 3 7% 4 4 3 3 3 5% 22%	1848
	11th to 20th	Night	32% 13% 3 6% 4 3 3 2 4 5% 26%	2200
	21st to end	Night	48% 16% 4 7% 3 3 3 1 2 3 11%	2200
October	1st to 10th	Night	37% 18% 6% 10% 4 3 2 2 2 3 13%	3792
	11th to 20th	Night	37% 19% 6% 11% 5% 3 3 2 2 3 9%	4197
	21st to end	Night	27% 18% 5% 11% 5% 4 3 2 3 3 19%	4629
November	1st to 10th	Night	41% 21% 4 7% 4 3 2 2 2 3 10%	2870
	11th to 20th	Night	32% 26% 5% 9% 5% 4 3 2 3 3 9%	3138
	21st to end	Night	32% 25% 5% 8% 4 4 2 2 3 3 12%	3150
December	1st to 10th	Night	31% 27% 6% 8% 4 3 3 2 2 3 12%	5040
	11th to 20th	Night	29% 24% 5% 10% 5% 3 2 2 3 3 14%	5710
	21st to end	Night	29% 25% 6% 13% 6% 5% 3 2 2 3 7%	7623

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	75% 6% 7% 9% 3	4125
	11th to 20th	Day	60% 6% 7% 15% 7% 5%	4140
	21st to end	Day	73% 5% 7% 11% 4	4765
February	1st to 10th	Day	68% 5% 5% 9% 9% 3	1680
	11th to 20th	Day	64% 6% 9% 14% 6% 2	1777
	21st to end	Day	63% 6% 9% 15% 5% 2	1609
March	1st to 10th	Day	65% 7% 6% 14% 8%	4596
	11th to 20th	Day	72% 8% 6% 10% 5%	5052
	21st to end	Day	59% 8% 9% 19% 5%	5712
April	1st to 10th	Day	76% 6% 7% 9% 2	2628
	11th to 20th	Day	70% 6% 7% 13% 4 1	2698
	21st to end	Day	70% 6% 10% 11% 3	2730
May	1st to 10th	Day	67% 11% 9% 11% 2	6872
	11th to 20th	Day	68% 9% 11% 10% 1	6889
	21st to end	Day	77% 9% 5% 8% 1	7571
June	1st to 10th	Day	72% 6% 11% 8% 3	3001
	11th to 20th	Day	73% 8% 9% 9% 1	3195
	21st to end	Day	74% 7% 11% 7% 1	3200
July	1st to 10th	Day	52% 9% 12% 20% 6%	7080
	11th to 20th	Day	52% 12% 23% 13% 1	6699
	21st to end	Day	51% 12% 26% 9% 2	7168
August	1st to 10th	Day	36% 8% 14% 27% 14% 1	4674
	11th to 20th	Day	59% 8% 11% 16% 5%	4362
	21st to end	Day	64% 9% 16% 9% 2	4663
September	1st to 10th	Day	67% 7% 14% 11% 2	2550
	11th to 20th	Day	65% 6% 13% 13% 3	2200
	21st to end	Day	80% 5% 7% 6% 2	2200
October	1st to 10th	Day	75% 8% 8% 6% 3	3408
	11th to 20th	Day	78% 10% 6% 4 2	2948
	21st to end	Day	68% 8% 9% 10% 5%	3170
November	1st to 10th	Day	81% 4 6% 6% 3	1648
	11th to 20th	Day	82% 4 5% 5% 4	1480
	21st to end	Day	76% 4 5% 10% 5% 1	1470
December	1st to 10th	Day	75% 6% 10% 8% 2	2360
	11th to 20th	Day	77% 4 6% 9% 3 1	2718
	21st to end	Day	84% 4 5% 3 3	3575
January	1st to 10th	Night	75% 6% 7% 9% 3	8770
	11th to 20th	Night	58% 7% 7% 15% 7% 5%	8820
	21st to end	Night	72% 6% 8% 9% 6%	9424
February	1st to 10th	Night	69% 4 6% 9% 10% 4	2940
	11th to 20th	Night	66% 4 8% 13% 7% 1	2741
	21st to end	Night	64% 5% 9% 14% 5% 2	2194
March	1st to 10th	Night	62% 7% 7% 16% 8% 1	5498
	11th to 20th	Night	76% 7% 6% 7% 4	5164
	21st to end	Night	57% 9% 7% 21% 6%	5499
April	1st to 10th	Night	72% 7% 9% 9% 3	1991
	11th to 20th	Night	67% 6% 8% 13% 4 1	1871
	21st to end	Night	66% 5% 14% 11% 4	1890
May	1st to 10th	Night	69% 11% 10% 9% 1	3303
	11th to 20th	Night	73% 8% 9% 8% 1	3229
	21st to end	Night	77% 7% 7% 6% 3	3547
June	1st to 10th	Night	68% 7% 11% 12% 2	1400
	11th to 20th	Night	76% 5% 12% 6% 1	1200
	21st to end	Night	72% 7% 14% 6% 2	1200
July	1st to 10th	Night	57% 6% 11% 18% 8%	2768
	11th to 20th	Night	54% 11% 24% 10%	3138
	21st to end	Night	53% 11% 24% 11% 1	3370
August	1st to 10th	Night	35% 8% 15% 32% 11%	2455
	11th to 20th	Night	60% 9% 14% 13% 3	2762
	21st to end	Night	71% 7% 13% 7% 1	3245
September	1st to 10th	Night	64% 8% 15% 11% 2	1848
	11th to 20th	Night	63% 5% 12% 17% 3	2200
	21st to end	Night	82% 4 5% 7% 3	2200
October	1st to 10th	Night	76% 6% 8% 7% 2	3792
	11th to 20th	Night	80% 7% 6% 5% 2	4197
	21st to end	Night	68% 8% 8% 11% 5%	4629
November	1st to 10th	Night	81% 3 6% 6% 3	2870
	11th to 20th	Night	81% 4 5% 5% 4	3138
	21st to end	Night	78% 4 6% 7% 5% 1	3150
December	1st to 10th	Night	79% 4 6% 8% 2	5040
	11th to 20th	Night	77% 4 7% 8% 4 1	5706
	21st to end	Night	83% 5% 6% 4 2	7623

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	38% 17% 24% 15% 5% 1	220
	11th to 20th	Day	50% 15% 16% 15% 3	220
	21st to end	Day	45% 11% 22% 16% 6%	322
February	1st to 10th	Day	38% 21% 23% 13% 4	430
	11th to 20th	Day	36% 16% 25% 14% 7% 1	425
	21st to end	Day	39% 21% 26% 9% 6% 1	355
March	1st to 10th	Day	33% 22% 25% 13% 6% 1	430
	11th to 20th	Day	33% 18% 25% 16% 6% 1	524
	21st to end	Day	33% 21% 25% 14% 6% 1	594
April	1st to 10th	Day	36% 22% 24% 12% 5% 1	540
	11th to 20th	Day	28% 19% 24% 18% 9% 2	532
	21st to end	Day	33% 21% 23% 14% 8% 2	540
May	1st to 10th	Day	32% 15% 24% 21% 7% 1	748
	11th to 20th	Day	28% 15% 23% 22% 9% 2	775
	21st to end	Day	31% 19% 22% 20% 7% 1	845
June	1st to 10th	Day	37% 18% 21% 16% 7%	731
	11th to 20th	Day	33% 18% 22% 20% 7% 1	730
	21st to end	Day	32% 14% 20% 24% 8% 1	730
July	1st to 10th	Day	30% 13% 20% 22% 14% 2	721
	11th to 20th	Day	30% 15% 21% 23% 10% 2	718
	21st to end	Day	31% 17% 19% 20% 11% 2	794
August	1st to 10th	Day	23% 13% 19% 26% 17% 3	726
	11th to 20th	Day	31% 15% 22% 22% 9% 1	620
	21st to end	Day	38% 13% 21% 16% 10% 3	583
September	1st to 10th	Day	37% 12% 20% 20% 11% 1	530
	11th to 20th	Day	36% 14% 21% 19% 9% 1	530
	21st to end	Day	51% 18% 19% 8% 4	530
October	1st to 10th	Day	40% 15% 18% 18% 8% 1	530
	11th to 20th	Day	46% 14% 21% 13% 5%	428
	21st to end	Day	44% 14% 20% 16% 6%	444
November	1st to 10th	Day	49% 19% 15% 13% 4 1	220
	11th to 20th	Day	45% 15% 19% 11% 9% 1	220
	21st to end	Day	50% 16% 12% 10% 10% 1	220
December	1st to 10th	Day	40% 16% 17% 17% 10%	220
	11th to 20th	Day	37% 17% 20% 18% 6% 1	220
	21st to end	Day	36% 18% 19% 16% 10%	242
January	1st to 10th	Night	44% 14% 23% 13% 5%	950
	11th to 20th	Night	51% 12% 20% 14% 3	950
	21st to end	Night	44% 12% 22% 16% 5% 1	1045
February	1st to 10th	Night	41% 14% 26% 13% 6%	950
	11th to 20th	Night	36% 13% 25% 19% 6% 1	865
	21st to end	Night	32% 15% 28% 17% 7% 1	692
March	1st to 10th	Night	31% 13% 28% 20% 7%	840
	11th to 20th	Night	35% 16% 25% 20% 4	840
	21st to end	Night	30% 14% 23% 22% 10% 1	877
April	1st to 10th	Night	32% 14% 22% 23% 8% 1	630
	11th to 20th	Night	31% 13% 20% 27% 9% 1	623
	21st to end	Night	34% 10% 26% 22% 7%	630
May	1st to 10th	Night	32% 12% 21% 22% 12% 1	448
	11th to 20th	Night	29% 10% 24% 27% 9%	414
	21st to end	Night	33% 13% 20% 21% 12%	455
June	1st to 10th	Night	33% 11% 25% 17% 14% 1	400
	11th to 20th	Night	36% 14% 20% 19% 11% 1	400
	21st to end	Night	35% 13% 17% 25% 9% 1	400
July	1st to 10th	Night	30% 11% 17% 26% 15% 1	390
	11th to 20th	Night	35% 13% 14% 20% 17% 1	388
	21st to end	Night	31% 12% 14% 25% 18% 1	438
August	1st to 10th	Night	27% 10% 10% 24% 25% 4	501
	11th to 20th	Night	32% 10% 13% 23% 20% 2	594
	21st to end	Night	40% 11% 16% 20% 13%	660
September	1st to 10th	Night	40% 9% 15% 24% 11% 1	604
	11th to 20th	Night	36% 10% 16% 21% 15% 2	800
	21st to end	Night	51% 14% 15% 13% 7%	800
October	1st to 10th	Night	41% 10% 22% 17% 9% 1	800
	11th to 20th	Night	48% 13% 19% 14% 7%	800
	21st to end	Night	43% 11% 19% 19% 7%	880
November	1st to 10th	Night	53% 14% 19% 12% 3	820
	11th to 20th	Night	45% 15% 21% 14% 4 1	945
	21st to end	Night	48% 13% 21% 10% 7% 1	950
December	1st to 10th	Night	39% 13% 22% 18% 7%	950
	11th to 20th	Night	41% 16% 21% 18% 3	950
	21st to end	Night	40% 17% 23% 14% 6%	1045

Page generated at 2026-05-28 22:53:25. Version ac07

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