Tiny Marsh Provincial Wildlife Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Tiny Marsh Provincial Wildlife Area clear sky chart from 2005-11-06 to 2025-07-21.

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	15% 11% 4 9% 5% 5% 5% 3 5% 6% 31%	120769
	Night	15% 14% 5% 11% 6% 5% 4 3 5% 6% 26%	118262
Transparency	Day	51% 8% 12% 18% 10% 1	124384
	Night	55% 8% 12% 16% 9% 1	122808
Seeing	Day	20% 16% 29% 21% 10% 3	15841
	Night	21% 13% 29% 26% 10% 1	24747

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	12% 17% 8% 16% 10% 6% 5% 4 4 5% 12%	3312
	11th to 20th	Day	9% 17% 8% 20% 11% 8% 6% 4 5% 4 8%	3870
	21st to end	Day	12% 18% 9% 17% 8% 7% 6% 3 5% 5% 10%	4466
February	1st to 10th	Day	12% 17% 7% 15% 9% 7% 5% 3 4 4 16%	1800
	11th to 20th	Day	13% 13% 6% 16% 7% 6% 6% 3 5% 6% 19%	1753
	21st to end	Day	14% 17% 7% 12% 6% 6% 6% 4 5% 5% 19%	1539
March	1st to 10th	Day	17% 11% 5% 10% 6% 5% 4 3 4 5% 28%	4918
	11th to 20th	Day	13% 14% 5% 9% 6% 5% 5% 4 6% 7% 27%	4980
	21st to end	Day	18% 13% 4 12% 4 3 4 3 4 5% 31%	5465
April	1st to 10th	Day	18% 13% 4 8% 5% 4 4 3 4 5% 31%	2348
	11th to 20th	Day	20% 11% 2 5% 4 4 4 3 4 5% 38%	2502
	21st to end	Day	20% 10% 3 7% 4 4 4 3 4 6% 35%	2600
May	1st to 10th	Day	17% 10% 3 7% 4 4 4 3 5% 6% 37%	5888
	11th to 20th	Day	13% 8% 3 8% 5% 4 4 3 5% 7% 38%	6305
	21st to end	Day	20% 8% 2 5% 4 4 4 3 5% 7% 38%	6949
June	1st to 10th	Day	17% 7% 2 5% 4 4 5% 4 6% 7% 39%	2800
	11th to 20th	Day	11% 6% 2 5% 5% 5% 4 5% 7% 9% 42%	2995
	21st to end	Day	16% 6% 2 6% 4 4 4 4 6% 8% 41%	3000
July	1st to 10th	Day	12% 5% 2 6% 5% 5% 5% 5% 7% 9% 39%	4910
	11th to 20th	Day	11% 5% 2 5% 4 4 4 4 6% 7% 48%	4661
	21st to end	Day	9% 6% 2 6% 5% 4 4 4 6% 8% 47%	4530
August	1st to 10th	Day	13% 7% 3 7% 4 5% 4 4 6% 8% 40%	4104
	11th to 20th	Day	12% 7% 3 6% 4 4 4 4 7% 9% 39%	4044
	21st to end	Day	9% 5% 2 6% 4 5% 5% 4 7% 9% 45%	4414
September	1st to 10th	Day	14% 7% 3 7% 4 5% 4 3 5% 8% 40%	2280
	11th to 20th	Day	12% 6% 2 5% 4 4 5% 3 5% 8% 45%	2142
	21st to end	Day	15% 7% 3 9% 5% 5% 4 3 6% 6% 37%	2066
October	1st to 10th	Day	20% 9% 3 7% 5% 4 4 3 5% 7% 34%	1900
	11th to 20th	Day	21% 12% 4 8% 6% 6% 5% 4 5% 6% 24%	1900
	21st to end	Day	28% 14% 5% 9% 6% 4 3 3 5% 6% 17%	2085
November	1st to 10th	Day	18% 15% 5% 9% 6% 4 5% 3 5% 7% 24%	1646
	11th to 20th	Day	16% 20% 5% 11% 5% 6% 6% 4 4 6% 17%	1600
	21st to end	Day	19% 23% 7% 12% 6% 5% 5% 3 4 4 11%	1600
December	1st to 10th	Day	15% 26% 11% 16% 8% 6% 4 3 2 3 6%	2600
	11th to 20th	Day	15% 22% 8% 17% 7% 5% 4 3 4 4 12%	2986
	21st to end	Day	24% 16% 6% 14% 7% 6% 5% 3 4 4 12%	3811
January	1st to 10th	Night	12% 22% 9% 18% 8% 6% 5% 3 4 4 8%	6606
	11th to 20th	Night	11% 17% 9% 20% 10% 8% 6% 4 5% 4 7%	5997
	21st to end	Night	13% 16% 8% 16% 8% 8% 5% 3 5% 5% 13%	6490
February	1st to 10th	Night	12% 20% 7% 17% 9% 4 5% 3 5% 4 14%	2600
	11th to 20th	Night	12% 17% 7% 15% 8% 6% 5% 4 4 5% 19%	2533
	21st to end	Night	14% 15% 5% 13% 7% 5% 5% 4 5% 6% 21%	2089
March	1st to 10th	Night	16% 13% 5% 10% 5% 5% 5% 4 5% 7% 26%	4920
	11th to 20th	Night	10% 13% 4 9% 6% 5% 5% 4 6% 7% 29%	4979
	21st to end	Night	20% 11% 6% 13% 5% 5% 4 3 4 4 26%	5467
April	1st to 10th	Night	19% 14% 4 10% 5% 4 4 3 4 6% 29%	2051
	11th to 20th	Night	19% 10% 3 7% 5% 4 4 3 4 6% 36%	1865
	21st to end	Night	17% 12% 4 8% 4 4 3 4 5% 6% 33%	1800
May	1st to 10th	Night	16% 9% 3 8% 5% 5% 4 4 5% 6% 36%	4053
	11th to 20th	Night	12% 7% 2 6% 5% 4 4 4 6% 8% 41%	3585
	21st to end	Night	19% 7% 2 6% 4 3 4 3 5% 6% 41%	3926
June	1st to 10th	Night	15% 7% 3 6% 5% 4 3 4 6% 8% 38%	1599
	11th to 20th	Night	11% 5% 2 6% 4 5% 6% 5% 6% 9% 42%	1400
	21st to end	Night	13% 7% 2 6% 5% 4 4 4 6% 9% 40%	1400
July	1st to 10th	Night	8% 6% 2 8% 4 5% 4 3 5% 7% 47%	2280
	11th to 20th	Night	14% 5% 2 5% 4 4 3 3 5% 6% 51%	2517
	21st to end	Night	8% 5% 2 5% 4 4 5% 4 5% 8% 48%	3019
August	1st to 10th	Night	10% 6% 3 5% 5% 4 5% 4 6% 7% 45%	2825
	11th to 20th	Night	13% 8% 2 6% 4 4 3 3 5% 7% 46%	2785
	21st to end	Night	14% 5% 2 5% 4 4 4 4 5% 7% 45%	3210
September	1st to 10th	Night	11% 6% 3 6% 4 4 4 3 6% 8% 44%	1900
	11th to 20th	Night	14% 6% 2 6% 3 3 4 3 5% 7% 47%	2034
	21st to end	Night	15% 8% 2 8% 5% 4 5% 4 5% 7% 38%	2112
October	1st to 10th	Night	18% 9% 3 9% 5% 4 4 3 4 6% 35%	2280
	11th to 20th	Night	23% 11% 3 8% 5% 5% 5% 3 5% 6% 26%	2280
	21st to end	Night	25% 13% 4 9% 6% 5% 4 4 5% 5% 19%	2510
November	1st to 10th	Night	20% 13% 4 9% 5% 6% 4 3 4 6% 27%	2651
	11th to 20th	Night	17% 20% 5% 10% 6% 5% 4 4 5% 5% 19%	2800
	21st to end	Night	21% 21% 6% 11% 7% 5% 4 3 4 5% 13%	2800
December	1st to 10th	Night	17% 28% 8% 17% 7% 5% 4 3 3 3 6%	4580
	11th to 20th	Night	14% 22% 8% 16% 7% 6% 4 4 5% 4 10%	5208
	21st to end	Night	22% 21% 7% 16% 6% 5% 4 3 3 3 11%	7111

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% 11% 10% 3	3313
	11th to 20th	Day	75% 10% 7% 6% 2	3904
	21st to end	Day	72% 9% 9% 7% 3	4466
February	1st to 10th	Day	70% 7% 9% 11% 2	1800
	11th to 20th	Day	65% 7% 11% 11% 5% 1	1762
	21st to end	Day	65% 8% 10% 12% 5%	1539
March	1st to 10th	Day	56% 8% 14% 11% 11% 1	4921
	11th to 20th	Day	56% 6% 14% 17% 6% 2	4980
	21st to end	Day	54% 7% 9% 17% 11% 1	5465
April	1st to 10th	Day	57% 6% 9% 18% 10% 1	2348
	11th to 20th	Day	49% 6% 9% 22% 13% 1	2502
	21st to end	Day	51% 6% 10% 18% 12% 3	2600
May	1st to 10th	Day	46% 7% 12% 19% 11% 5%	5897
	11th to 20th	Day	45% 9% 11% 16% 19% 1	6309
	21st to end	Day	45% 6% 11% 20% 14% 3	6949
June	1st to 10th	Day	43% 8% 12% 22% 15% 1	2800
	11th to 20th	Day	37% 9% 14% 24% 15% 1	2995
	21st to end	Day	41% 8% 14% 23% 13% 1	3000
July	1st to 10th	Day	39% 8% 17% 21% 13% 1	4836
	11th to 20th	Day	33% 8% 14% 34% 11% 1	4583
	21st to end	Day	35% 7% 11% 27% 18% 1	4385
August	1st to 10th	Day	41% 7% 15% 24% 12% 1	4091
	11th to 20th	Day	40% 9% 18% 23% 10%	4083
	21st to end	Day	34% 8% 14% 33% 10% 1	4414
September	1st to 10th	Day	41% 8% 14% 25% 10% 1	2280
	11th to 20th	Day	37% 8% 14% 27% 13%	2142
	21st to end	Day	47% 9% 13% 24% 8%	2066
October	1st to 10th	Day	45% 6% 13% 25% 10% 1	3160
	11th to 20th	Day	48% 6% 14% 21% 10%	3140
	21st to end	Day	63% 7% 12% 13% 4	3411
November	1st to 10th	Day	57% 9% 13% 15% 6%	1646
	11th to 20th	Day	63% 10% 11% 11% 5%	1600
	21st to end	Day	73% 9% 9% 7% 1	1600
December	1st to 10th	Day	81% 6% 9% 3	2600
	11th to 20th	Day	72% 9% 9% 9% 2	2986
	21st to end	Day	74% 10% 4 7% 5%	3811
January	1st to 10th	Night	71% 9% 9% 8% 3	6606
	11th to 20th	Night	73% 10% 8% 7% 3	6038
	21st to end	Night	68% 9% 10% 7% 6%	6490
February	1st to 10th	Night	69% 8% 11% 11% 2	2600
	11th to 20th	Night	64% 7% 11% 14% 3	2535
	21st to end	Night	60% 7% 13% 14% 6%	2089
March	1st to 10th	Night	55% 7% 11% 15% 10% 2	4930
	11th to 20th	Night	48% 8% 19% 16% 7% 1	4980
	21st to end	Night	55% 9% 10% 15% 10% 1	5467
April	1st to 10th	Night	57% 5% 10% 17% 10% 1	2051
	11th to 20th	Night	50% 6% 8% 20% 15% 2	1865
	21st to end	Night	50% 7% 11% 15% 16% 1	1800
May	1st to 10th	Night	46% 8% 12% 14% 15% 5%	4060
	11th to 20th	Night	39% 9% 13% 22% 17% 1	3586
	21st to end	Night	43% 7% 11% 25% 13% 1	3927
June	1st to 10th	Night	42% 7% 12% 21% 17% 2	1599
	11th to 20th	Night	36% 8% 14% 22% 20% 1	1400
	21st to end	Night	40% 8% 15% 22% 14% 1	1400
July	1st to 10th	Night	35% 6% 14% 25% 17% 3	2245
	11th to 20th	Night	33% 6% 12% 35% 14% 1	2472
	21st to end	Night	33% 7% 13% 30% 16% 1	2923
August	1st to 10th	Night	36% 6% 14% 27% 16% 1	2814
	11th to 20th	Night	38% 6% 17% 25% 13% 1	2812
	21st to end	Night	37% 6% 12% 32% 12% 1	3210
September	1st to 10th	Night	35% 8% 16% 28% 12% 1	1900
	11th to 20th	Night	34% 8% 15% 28% 16%	2034
	21st to end	Night	44% 9% 13% 24% 10%	2112
October	1st to 10th	Night	40% 6% 11% 24% 18% 1	3800
	11th to 20th	Night	45% 7% 17% 22% 11%	3779
	21st to end	Night	52% 8% 15% 20% 5%	4134
November	1st to 10th	Night	54% 8% 13% 19% 6%	2651
	11th to 20th	Night	63% 9% 12% 11% 4 1	2800
	21st to end	Night	68% 11% 12% 8% 1	2800
December	1st to 10th	Night	79% 8% 9% 4 1	4580
	11th to 20th	Night	73% 8% 9% 8% 1	5208
	21st to end	Night	77% 5% 7% 7% 4	7111

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	16% 27% 37% 14% 5% 1	200
	11th to 20th	Day	19% 27% 34% 15% 4 1	267
	21st to end	Day	25% 22% 32% 19% 2	330
February	1st to 10th	Day	25% 31% 30% 11% 3	300
	11th to 20th	Day	24% 28% 37% 9% 2	300
	21st to end	Day	31% 29% 31% 10%	249
March	1st to 10th	Day	22% 22% 36% 15% 3	486
	11th to 20th	Day	24% 21% 33% 18% 3 1	500
	21st to end	Day	31% 18% 28% 16% 7%	550
April	1st to 10th	Day	27% 20% 33% 14% 6% 1	500
	11th to 20th	Day	34% 17% 22% 17% 6% 4	492
	21st to end	Day	27% 18% 30% 15% 7% 2	500
May	1st to 10th	Day	21% 16% 32% 20% 8% 3	503
	11th to 20th	Day	17% 13% 30% 23% 14% 3	527
	21st to end	Day	19% 12% 29% 22% 14% 4	573
June	1st to 10th	Day	20% 14% 29% 25% 11% 1	530
	11th to 20th	Day	14% 12% 32% 28% 11% 3	725
	21st to end	Day	19% 9% 33% 25% 11% 3	730
July	1st to 10th	Day	12% 8% 29% 31% 17% 4	721
	11th to 20th	Day	13% 9% 27% 29% 15% 7%	576
	21st to end	Day	8% 7% 28% 35% 15% 6%	532
August	1st to 10th	Day	12% 8% 23% 28% 20% 10%	486
	11th to 20th	Day	14% 6% 22% 27% 20% 11%	479
	21st to end	Day	14% 9% 26% 29% 17% 6%	539
September	1st to 10th	Day	15% 10% 26% 26% 16% 8%	490
	11th to 20th	Day	11% 8% 25% 23% 21% 12%	490
	21st to end	Day	15% 13% 28% 24% 14% 5%	490
October	1st to 10th	Day	23% 14% 25% 20% 13% 4	490
	11th to 20th	Day	21% 23% 30% 18% 8%	490
	21st to end	Day	33% 21% 28% 15% 3	534
November	1st to 10th	Day	27% 22% 29% 17% 4 1	242
	11th to 20th	Day	23% 28% 35% 13% 1 2	200
	21st to end	Day	29% 22% 37% 12% 1	200
December	1st to 10th	Day	28% 24% 33% 12% 4 1	200
	11th to 20th	Day	28% 30% 28% 12% 3 1	200
	21st to end	Day	29% 28% 31% 11% 1	220
January	1st to 10th	Night	23% 23% 34% 14% 5%	915
	11th to 20th	Night	26% 18% 32% 20% 4	800
	21st to end	Night	19% 14% 34% 25% 6% 1	880
February	1st to 10th	Night	21% 20% 37% 20% 3	800
	11th to 20th	Night	21% 17% 36% 21% 4	783
	21st to end	Night	23% 20% 30% 23% 4	660
March	1st to 10th	Night	21% 18% 35% 22% 4	800
	11th to 20th	Night	21% 17% 35% 21% 5% 1	800
	21st to end	Night	22% 15% 30% 25% 8%	880
April	1st to 10th	Night	26% 14% 33% 23% 3	800
	11th to 20th	Night	24% 14% 28% 23% 10% 1	681
	21st to end	Night	23% 13% 27% 27% 11%	600
May	1st to 10th	Night	20% 7% 23% 37% 12% 1	600
	11th to 20th	Night	19% 6% 30% 35% 9% 1	404
	21st to end	Night	14% 5% 27% 40% 14%	433
June	1st to 10th	Night	17% 7% 28% 37% 11% 1	400
	11th to 20th	Night	14% 7% 24% 40% 16%	400
	21st to end	Night	16% 4 26% 37% 17% 1	400
July	1st to 10th	Night	9% 6% 16% 49% 19% 1	390
	11th to 20th	Night	10% 5% 24% 39% 20% 1	388
	21st to end	Night	10% 3 24% 38% 24% 1	582
August	1st to 10th	Night	11% 5% 17% 39% 26% 2	567
	11th to 20th	Night	9% 4 18% 37% 29% 3	564
	21st to end	Night	15% 6% 22% 31% 24% 1	674
September	1st to 10th	Night	14% 5% 25% 33% 20% 4	760
	11th to 20th	Night	15% 5% 22% 32% 21% 5%	760
	21st to end	Night	17% 10% 22% 31% 17% 4	760
October	1st to 10th	Night	23% 9% 30% 23% 14% 1	760
	11th to 20th	Night	27% 14% 28% 22% 8% 1	760
	21st to end	Night	30% 17% 32% 18% 4	836
November	1st to 10th	Night	26% 14% 30% 22% 7% 1	780
	11th to 20th	Night	25% 22% 29% 19% 6% 1	800
	21st to end	Night	30% 17% 30% 19% 3	800
December	1st to 10th	Night	29% 22% 31% 14% 3 1	800
	11th to 20th	Night	25% 19% 37% 15% 3	800
	21st to end	Night	30% 20% 30% 18% 2	930

Page generated at 2025-07-18 01:10:00. Version ac07

Copyright © 2025 Attilla Danko.