Labrador City
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Labrador City clear sky chart from 2005-11-06 to 2024-11-11.

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	17% 15% 5% 12% 7% 6% 5% 4 5% 6% 18%	102156
	Night	14% 15% 5% 12% 7% 6% 6% 4 6% 7% 18%	97151
Transparency	Day	64% 7% 10% 13% 5%	105485
	Night	63% 7% 10% 13% 6% 1	101916
Seeing	Day	23% 11% 26% 23% 13% 4	16171
	Night	20% 10% 30% 27% 11% 2	23660

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% 12% 4 14% 11% 7% 5% 5% 10% 11% 13%	2207
	11th to 20th	Day	6% 15% 7% 19% 8% 5% 7% 4 5% 10% 15%	2210
	21st to end	Day	3 8% 5% 15% 9% 6% 7% 6% 7% 12% 22%	2533
February	1st to 10th	Day	3 13% 5% 11% 7% 7% 6% 7% 11% 11% 19%	1539
	11th to 20th	Day	4 15% 7% 14% 9% 7% 7% 5% 7% 10% 14%	1663
	21st to end	Day	5% 16% 5% 11% 7% 8% 8% 5% 9% 10% 18%	1427
March	1st to 10th	Day	7% 16% 5% 14% 8% 9% 7% 5% 7% 8% 14%	3170
	11th to 20th	Day	10% 27% 11% 17% 6% 4 5% 3 3 5% 10%	3480
	21st to end	Day	14% 21% 8% 13% 6% 5% 8% 4 4 4 13%	3816
April	1st to 10th	Day	15% 18% 6% 15% 8% 7% 6% 3 4 4 13%	2393
	11th to 20th	Day	11% 16% 4 13% 7% 6% 4 4 5% 5% 24%	2442
	21st to end	Day	17% 17% 5% 13% 7% 5% 4 4 5% 5% 18%	2470
May	1st to 10th	Day	18% 24% 6% 12% 5% 4 4 2 3 4 18%	4575
	11th to 20th	Day	19% 12% 5% 10% 6% 5% 5% 3 5% 6% 24%	4715
	21st to end	Day	31% 16% 6% 9% 4 4 4 3 4 4 14%	5185
June	1st to 10th	Day	24% 14% 4 8% 5% 4 4 3 4 6% 24%	2850
	11th to 20th	Day	24% 11% 4 9% 5% 5% 5% 4 6% 6% 22%	2850
	21st to end	Day	25% 9% 3 9% 6% 6% 6% 3 5% 6% 20%	2850
July	1st to 10th	Day	19% 9% 3 7% 5% 5% 5% 4 6% 7% 29%	4760
	11th to 20th	Day	24% 9% 3 9% 6% 6% 5% 4 6% 5% 24%	4760
	21st to end	Day	16% 10% 4 11% 9% 8% 7% 5% 7% 6% 17%	5162
August	1st to 10th	Day	17% 10% 4 11% 7% 7% 6% 4 7% 6% 21%	4603
	11th to 20th	Day	20% 10% 4 9% 7% 7% 6% 5% 6% 6% 21%	4045
	21st to end	Day	19% 9% 2 7% 5% 4 4 4 5% 7% 32%	4532
September	1st to 10th	Day	24% 12% 3 9% 6% 6% 4 3 6% 6% 20%	2387
	11th to 20th	Day	23% 14% 4 11% 7% 5% 4 3 5% 6% 18%	2113
	21st to end	Day	20% 19% 6% 11% 5% 5% 4 3 4 6% 18%	2090
October	1st to 10th	Day	22% 18% 6% 11% 5% 5% 4 2 5% 5% 17%	1914
	11th to 20th	Day	26% 20% 6% 11% 6% 4 4 2 3 5% 14%	1817
	21st to end	Day	21% 22% 9% 13% 6% 5% 4 3 3 3 12%	1815
November	1st to 10th	Day	20% 18% 7% 19% 9% 5% 5% 3 3 4 7%	1565
	11th to 20th	Day	15% 20% 7% 18% 9% 7% 5% 4 4 3 8%	1459
	21st to end	Day	14% 17% 7% 16% 11% 7% 8% 4 5% 5% 8%	1330
December	1st to 10th	Day	8% 16% 6% 17% 11% 8% 6% 5% 6% 6% 10%	1330
	11th to 20th	Day	10% 17% 6% 12% 10% 9% 8% 5% 7% 7% 10%	1668
	21st to end	Day	7% 14% 6% 15% 9% 11% 8% 4 7% 6% 13%	2431
January	1st to 10th	Night	5% 11% 4 13% 10% 8% 7% 6% 10% 12% 14%	4748
	11th to 20th	Night	8% 15% 6% 17% 8% 7% 6% 5% 7% 9% 11%	4760
	21st to end	Night	3 8% 4 14% 10% 8% 8% 6% 9% 10% 22%	5130
February	1st to 10th	Night	3 12% 5% 10% 10% 8% 7% 7% 8% 10% 19%	2641
	11th to 20th	Night	5% 16% 7% 14% 8% 7% 6% 4 8% 10% 15%	2403
	21st to end	Night	6% 13% 5% 13% 8% 6% 6% 5% 8% 10% 18%	2026
March	1st to 10th	Night	6% 16% 6% 11% 6% 8% 6% 6% 8% 7% 21%	3669
	11th to 20th	Night	11% 29% 9% 13% 5% 5% 4 3 4 4 12%	3479
	21st to end	Night	12% 23% 7% 13% 6% 5% 5% 4 4 4 18%	3816
April	1st to 10th	Night	13% 17% 7% 14% 7% 6% 5% 3 4 4 18%	1786
	11th to 20th	Night	14% 15% 4 10% 6% 4 5% 3 4 5% 29%	1688
	21st to end	Night	17% 13% 5% 11% 7% 5% 5% 4 4 5% 24%	1710
May	1st to 10th	Night	20% 23% 7% 12% 5% 3 3 3 3 3 17%	2406
	11th to 20th	Night	21% 11% 4 8% 4 4 4 3 5% 5% 30%	2188
	21st to end	Night	29% 16% 6% 9% 5% 4 3 3 4 4 17%	2401
June	1st to 10th	Night	19% 11% 4 8% 5% 5% 5% 3 5% 6% 29%	1330
	11th to 20th	Night	22% 11% 5% 8% 5% 6% 5% 4 4 6% 24%	1330
	21st to end	Night	23% 10% 3 10% 6% 5% 5% 4 6% 6% 24%	1330
July	1st to 10th	Night	17% 8% 2 7% 5% 4 5% 4 6% 7% 35%	2210
	11th to 20th	Night	19% 8% 4 9% 5% 6% 5% 3 6% 7% 29%	2210
	21st to end	Night	13% 10% 4 8% 6% 6% 5% 5% 7% 8% 27%	2402
August	1st to 10th	Night	14% 8% 4 9% 6% 6% 7% 5% 6% 8% 27%	2308
	11th to 20th	Night	19% 10% 5% 10% 7% 6% 6% 5% 7% 8% 18%	2773
	21st to end	Night	14% 7% 2 6% 4 5% 5% 4 7% 9% 36%	3124
September	1st to 10th	Night	20% 11% 3 9% 6% 6% 5% 4 5% 6% 26%	1792
	11th to 20th	Night	22% 12% 4 9% 5% 4 5% 4 6% 6% 23%	2065
	21st to end	Night	21% 12% 4 9% 6% 6% 5% 4 5% 6% 22%	2090
October	1st to 10th	Night	20% 17% 4 8% 5% 4 5% 3 5% 6% 22%	2266
	11th to 20th	Night	24% 20% 6% 10% 5% 5% 3 2 4 6% 15%	2361
	21st to end	Night	23% 17% 6% 13% 6% 5% 4 4 5% 4 14%	2783
November	1st to 10th	Night	17% 20% 7% 18% 10% 5% 5% 3 3 3 8%	2733
	11th to 20th	Night	17% 19% 7% 15% 9% 8% 5% 3 4 4 8%	2726
	21st to end	Night	16% 18% 7% 14% 9% 7% 7% 5% 5% 6% 8%	2850
December	1st to 10th	Night	9% 17% 6% 15% 10% 9% 8% 5% 6% 6% 9%	2850
	11th to 20th	Night	13% 17% 5% 13% 10% 8% 6% 4 5% 8% 10%	3531
	21st to end	Night	7% 15% 8% 15% 9% 12% 8% 5% 5% 6% 10%	5236

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	59% 6% 7% 18% 10%	2208
	11th to 20th	Day	65% 7% 10% 12% 5%	2210
	21st to end	Day	51% 8% 7% 11% 20% 3	2533
February	1st to 10th	Day	51% 7% 10% 21% 9% 1	1539
	11th to 20th	Day	62% 7% 8% 14% 9%	1671
	21st to end	Day	56% 6% 10% 15% 11% 2	1427
March	1st to 10th	Day	64% 6% 8% 11% 10% 1	3174
	11th to 20th	Day	79% 4 5% 8% 4 1	3480
	21st to end	Day	73% 6% 6% 8% 6% 1	3816
April	1st to 10th	Day	73% 7% 8% 8% 4	2393
	11th to 20th	Day	61% 6% 8% 13% 11% 1	2442
	21st to end	Day	67% 7% 10% 9% 7%	2470
May	1st to 10th	Day	71% 7% 9% 11% 3	4590
	11th to 20th	Day	56% 9% 11% 18% 5%	4719
	21st to end	Day	72% 7% 8% 9% 4	5185
June	1st to 10th	Day	60% 6% 11% 15% 6% 1	2850
	11th to 20th	Day	60% 8% 11% 14% 6%	2850
	21st to end	Day	63% 8% 12% 13% 4	2850
July	1st to 10th	Day	53% 7% 12% 22% 6%	4685
	11th to 20th	Day	60% 6% 12% 16% 5%	4679
	21st to end	Day	63% 9% 14% 13% 1	4998
August	1st to 10th	Day	60% 8% 13% 15% 3	4588
	11th to 20th	Day	60% 7% 13% 15% 4	4084
	21st to end	Day	50% 8% 19% 19% 4	4532
September	1st to 10th	Day	63% 8% 14% 12% 3	2387
	11th to 20th	Day	67% 7% 12% 12% 2	2113
	21st to end	Day	67% 7% 11% 12% 2	2090
October	1st to 10th	Day	63% 6% 12% 17% 2	3174
	11th to 20th	Day	78% 5% 6% 9% 1	2994
	21st to end	Day	75% 5% 7% 10% 2	2971
November	1st to 10th	Day	81% 7% 7% 4 1	1565
	11th to 20th	Day	80% 7% 8% 3 1 1	1459
	21st to end	Day	77% 9% 6% 6% 2	1330
December	1st to 10th	Day	70% 11% 8% 7% 2 1	1330
	11th to 20th	Day	68% 11% 10% 8% 4	1668
	21st to end	Day	68% 7% 7% 11% 5% 1	2431
January	1st to 10th	Night	56% 9% 8% 17% 9% 1	4748
	11th to 20th	Night	67% 9% 9% 10% 5%	4760
	21st to end	Night	54% 7% 10% 12% 13% 5%	5130
February	1st to 10th	Night	55% 8% 9% 16% 11% 1	2641
	11th to 20th	Night	63% 6% 8% 14% 9%	2406
	21st to end	Night	57% 7% 10% 14% 10% 2	2026
March	1st to 10th	Night	56% 7% 9% 16% 11% 1	3678
	11th to 20th	Night	74% 5% 6% 8% 5% 1	3480
	21st to end	Night	70% 5% 6% 8% 11% 1	3816
April	1st to 10th	Night	68% 5% 8% 10% 8% 1	1786
	11th to 20th	Night	56% 6% 9% 15% 12% 2	1688
	21st to end	Night	62% 6% 10% 15% 7%	1710
May	1st to 10th	Night	72% 5% 7% 13% 2	2411
	11th to 20th	Night	52% 8% 12% 21% 7%	2189
	21st to end	Night	69% 7% 7% 12% 4	2402
June	1st to 10th	Night	54% 8% 12% 18% 8%	1330
	11th to 20th	Night	58% 8% 11% 18% 4	1330
	21st to end	Night	58% 9% 11% 17% 5%	1330
July	1st to 10th	Night	46% 8% 16% 25% 4	2175
	11th to 20th	Night	54% 7% 13% 18% 8%	2168
	21st to end	Night	50% 11% 15% 21% 3	2325
August	1st to 10th	Night	53% 10% 16% 19% 2	2299
	11th to 20th	Night	61% 9% 15% 13% 2	2800
	21st to end	Night	42% 8% 20% 25% 5%	3124
September	1st to 10th	Night	59% 8% 14% 17% 2	1792
	11th to 20th	Night	59% 10% 15% 15% 3	2065
	21st to end	Night	60% 8% 14% 15% 2	2090
October	1st to 10th	Night	57% 6% 15% 18% 3	3786
	11th to 20th	Night	73% 6% 9% 9% 3	3923
	21st to end	Night	75% 6% 7% 8% 3 1	4581
November	1st to 10th	Night	80% 6% 7% 6% 1	2733
	11th to 20th	Night	79% 7% 6% 6% 1	2726
	21st to end	Night	75% 9% 9% 6% 2	2850
December	1st to 10th	Night	73% 10% 8% 6% 2	2850
	11th to 20th	Night	71% 7% 10% 8% 5%	3532
	21st to end	Night	71% 8% 7% 6% 6% 2	5236

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	7% 8% 31% 28% 20% 6%	180
	11th to 20th	Day	9% 11% 32% 31% 15% 3	180
	21st to end	Day	11% 8% 37% 29% 11% 4	198
February	1st to 10th	Day	9% 8% 37% 23% 16% 8%	199
	11th to 20th	Day	6% 11% 37% 29% 14% 3	366
	21st to end	Day	11% 11% 35% 27% 14% 3	314
March	1st to 10th	Day	12% 14% 30% 24% 16% 4	460
	11th to 20th	Day	13% 14% 28% 26% 15% 4	460
	21st to end	Day	15% 16% 34% 23% 9% 3	506
April	1st to 10th	Day	20% 13% 33% 22% 9% 3	460
	11th to 20th	Day	15% 14% 27% 27% 11% 6%	452
	21st to end	Day	22% 13% 27% 21% 12% 5%	460
May	1st to 10th	Day	30% 9% 22% 23% 10% 5%	653
	11th to 20th	Day	19% 12% 25% 20% 18% 7%	674
	21st to end	Day	28% 12% 24% 22% 12% 3	735
June	1st to 10th	Day	26% 8% 20% 27% 16% 3	680
	11th to 20th	Day	29% 9% 22% 22% 14% 4	680
	21st to end	Day	28% 8% 25% 20% 14% 4	680
July	1st to 10th	Day	24% 8% 25% 22% 15% 6%	670
	11th to 20th	Day	29% 9% 21% 25% 13% 3	668
	21st to end	Day	25% 6% 20% 27% 16% 6%	740
August	1st to 10th	Day	29% 8% 20% 23% 15% 5%	610
	11th to 20th	Day	23% 8% 19% 22% 22% 6%	479
	21st to end	Day	26% 9% 20% 23% 16% 6%	539
September	1st to 10th	Day	30% 14% 28% 18% 7% 2	490
	11th to 20th	Day	25% 14% 30% 21% 8% 2	490
	21st to end	Day	24% 17% 32% 15% 8% 3	490
October	1st to 10th	Day	25% 19% 29% 17% 7% 3	397
	11th to 20th	Day	35% 12% 23% 20% 7% 3	390
	21st to end	Day	29% 14% 24% 19% 10% 2	429
November	1st to 10th	Day	26% 17% 32% 19% 4 2	395
	11th to 20th	Day	23% 13% 31% 23% 8% 2	309
	21st to end	Day	12% 16% 39% 20% 10% 3	180
December	1st to 10th	Day	15% 11% 21% 29% 20% 4	180
	11th to 20th	Day	16% 13% 37% 22% 9% 3	180
	21st to end	Day	14% 13% 33% 23% 15% 3	198
January	1st to 10th	Night	12% 8% 31% 30% 15% 3	850
	11th to 20th	Night	13% 10% 36% 31% 9% 2	850
	21st to end	Night	10% 7% 35% 33% 13% 2	903
February	1st to 10th	Night	7% 9% 31% 34% 15% 4	760
	11th to 20th	Night	11% 10% 35% 28% 13% 2	743
	21st to end	Night	12% 8% 34% 28% 14% 3	628
March	1st to 10th	Night	10% 9% 33% 30% 15% 3	760
	11th to 20th	Night	14% 10% 35% 27% 14% 1	760
	21st to end	Night	16% 13% 34% 27% 9% 2	836
April	1st to 10th	Night	20% 9% 35% 29% 6% 1	622
	11th to 20th	Night	20% 7% 32% 27% 10% 4	564
	21st to end	Night	24% 10% 28% 28% 9% 2	570
May	1st to 10th	Night	27% 8% 25% 28% 10% 1	503
	11th to 20th	Night	24% 8% 25% 26% 15% 3	374
	21st to end	Night	27% 11% 25% 26% 10% 1	411
June	1st to 10th	Night	21% 6% 25% 36% 11%	380
	11th to 20th	Night	25% 10% 24% 29% 13%	380
	21st to end	Night	26% 6% 23% 29% 15% 1	380
July	1st to 10th	Night	25% 6% 22% 32% 14% 1	370
	11th to 20th	Night	23% 7% 24% 35% 11%	368
	21st to end	Night	19% 6% 20% 34% 18% 2	416
August	1st to 10th	Night	26% 6% 16% 34% 17% 1	378
	11th to 20th	Night	23% 7% 22% 30% 18% 2	553
	21st to end	Night	25% 7% 25% 29% 12% 2	627
September	1st to 10th	Night	26% 10% 30% 27% 6% 1	570
	11th to 20th	Night	27% 11% 28% 26% 7% 1	735
	21st to end	Night	25% 14% 32% 21% 8%	760
October	1st to 10th	Night	31% 14% 28% 21% 5%	760
	11th to 20th	Night	34% 9% 23% 24% 8% 2	760
	21st to end	Night	32% 12% 27% 20% 8% 2	871
November	1st to 10th	Night	28% 17% 30% 19% 6% 1	880
	11th to 20th	Night	25% 15% 30% 20% 9% 1	853
	21st to end	Night	23% 10% 32% 24% 10% 1	850
December	1st to 10th	Night	17% 9% 35% 26% 10% 3	850
	11th to 20th	Night	16% 10% 35% 28% 10% 1	850
	21st to end	Night	16% 12% 27% 28% 14% 2	935

Page generated at 2024-11-08 07:44:47. Version ac07

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