Mactaquac Provincial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mactaquac Provincial Park clear sky chart from 2005-11-06 to 2025-01-22.

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	19% 9% 3 7% 5% 4 4 4 5% 7% 33%	104946
	Night	19% 10% 3 7% 5% 4 4 4 5% 6% 34%	104502
Transparency	Day	50% 5% 12% 21% 11% 1	108462
	Night	50% 6% 12% 21% 11% 1	109076
Seeing	Day	28% 16% 30% 18% 7% 1	16450
	Night	26% 14% 30% 23% 6%	24517

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	14% 12% 5% 10% 5% 6% 4 3 5% 5% 31%	2277
	11th to 20th	Day	15% 11% 4 12% 6% 4 4 2 4 4 32%	2573
	21st to end	Day	12% 9% 3 8% 5% 5% 5% 4 6% 7% 35%	2943
February	1st to 10th	Day	15% 11% 4 8% 7% 5% 4 4 5% 7% 30%	1710
	11th to 20th	Day	16% 13% 3 9% 5% 5% 5% 4 5% 5% 28%	1663
	21st to end	Day	11% 14% 3 9% 5% 5% 4 4 6% 6% 34%	1544
March	1st to 10th	Day	23% 14% 3 6% 4 3 3 3 4 5% 29%	3261
	11th to 20th	Day	18% 16% 5% 10% 6% 6% 4 3 5% 6% 22%	3480
	21st to end	Day	27% 13% 4 8% 4 4 3 3 4 7% 22%	3816
April	1st to 10th	Day	22% 15% 3 7% 4 4 4 3 5% 6% 28%	2234
	11th to 20th	Day	20% 10% 3 6% 4 4 4 3 5% 6% 34%	2442
	21st to end	Day	26% 10% 3 6% 3 4 4 3 4 5% 32%	2470
May	1st to 10th	Day	20% 10% 3 8% 5% 5% 5% 4 5% 6% 29%	4106
	11th to 20th	Day	21% 8% 3 8% 5% 5% 5% 3 5% 6% 32%	4284
	21st to end	Day	17% 7% 3 7% 5% 5% 5% 4 6% 8% 33%	5049
June	1st to 10th	Day	25% 9% 3 8% 4 4 4 4 5% 7% 27%	2850
	11th to 20th	Day	21% 7% 3 6% 5% 3 4 3 5% 7% 36%	2850
	21st to end	Day	27% 9% 3 6% 4 5% 4 4 5% 6% 27%	2850
July	1st to 10th	Day	15% 6% 3 7% 6% 6% 6% 4 7% 9% 31%	4760
	11th to 20th	Day	18% 7% 2 6% 4 5% 5% 4 6% 8% 34%	4712
	21st to end	Day	16% 8% 2 6% 5% 5% 5% 4 6% 7% 36%	4639
August	1st to 10th	Day	19% 8% 2 8% 5% 5% 5% 4 5% 7% 32%	4105
	11th to 20th	Day	15% 7% 3 9% 6% 5% 5% 5% 6% 7% 31%	4045
	21st to end	Day	15% 5% 2 6% 4 4 4 4 6% 8% 43%	4532
September	1st to 10th	Day	13% 5% 2 5% 4 4 5% 4 5% 7% 45%	2258
	11th to 20th	Day	17% 6% 2 6% 4 3 4 3 4 5% 47%	2090
	21st to end	Day	19% 6% 2 6% 4 3 4 3 4 6% 42%	2090
October	1st to 10th	Day	18% 8% 2 6% 4 4 4 3 5% 6% 39%	1950
	11th to 20th	Day	21% 7% 2 6% 4 4 4 3 5% 7% 36%	1900
	21st to end	Day	21% 10% 3 8% 5% 4 5% 3 4 5% 32%	1943
November	1st to 10th	Day	21% 8% 3 7% 4 4 3 3 4 7% 36%	1715
	11th to 20th	Day	21% 8% 3 6% 4 4 5% 3 5% 8% 33%	1600
	21st to end	Day	21% 12% 3 9% 4 4 5% 3 4 5% 30%	1600
December	1st to 10th	Day	21% 11% 3 7% 3 4 4 4 5% 7% 32%	2511
	11th to 20th	Day	22% 10% 3 8% 5% 4 3 2 4 5% 34%	2618
	21st to end	Day	19% 13% 4 7% 4 4 4 3 4 5% 33%	3476
January	1st to 10th	Night	13% 12% 4 9% 5% 5% 4 4 5% 8% 31%	4898
	11th to 20th	Night	15% 11% 4 11% 7% 5% 5% 4 5% 6% 29%	4603
	21st to end	Night	13% 11% 4 8% 5% 4 4 4 6% 7% 32%	4735
February	1st to 10th	Night	15% 13% 3 7% 5% 4 4 4 6% 6% 32%	2470
	11th to 20th	Night	16% 12% 4 8% 6% 5% 5% 4 6% 5% 28%	2403
	21st to end	Night	15% 13% 3 7% 6% 6% 4 4 5% 5% 32%	1908
March	1st to 10th	Night	23% 13% 4 7% 5% 6% 5% 3 4 3 28%	3579
	11th to 20th	Night	20% 13% 4 8% 5% 4 5% 4 5% 7% 24%	3479
	21st to end	Night	30% 10% 3 7% 4 3 3 3 5% 5% 27%	3816
April	1st to 10th	Night	24% 12% 2 6% 5% 4 4 3 4 5% 31%	1942
	11th to 20th	Night	23% 8% 2 5% 4 4 4 3 5% 5% 36%	1688
	21st to end	Night	25% 9% 3 6% 4 3 4 3 4 7% 32%	1710
May	1st to 10th	Night	21% 8% 2 6% 5% 5% 5% 4 6% 6% 32%	2834
	11th to 20th	Night	19% 7% 3 6% 5% 4 5% 4 5% 8% 34%	2614
	21st to end	Night	16% 6% 3 7% 5% 5% 5% 4 6% 8% 36%	2564
June	1st to 10th	Night	24% 8% 2 6% 5% 5% 6% 3 4 7% 28%	1330
	11th to 20th	Night	18% 7% 2 6% 5% 3 4 4 6% 7% 36%	1330
	21st to end	Night	26% 7% 2 6% 4 4 4 3 4 6% 32%	1330
July	1st to 10th	Night	13% 7% 2 6% 5% 5% 6% 6% 8% 7% 36%	2210
	11th to 20th	Night	18% 8% 2 6% 4 5% 4 3 6% 9% 35%	2240
	21st to end	Night	14% 6% 2 7% 4 5% 5% 4 6% 7% 39%	2881
August	1st to 10th	Night	18% 6% 3 9% 5% 5% 5% 4 6% 8% 30%	2825
	11th to 20th	Night	13% 7% 3 8% 5% 5% 5% 5% 6% 9% 34%	2782
	21st to end	Night	14% 5% 2 5% 4 5% 4 4 5% 6% 46%	3124
September	1st to 10th	Night	15% 5% 2 6% 4 3 4 4 6% 7% 46%	1919
	11th to 20th	Night	16% 6% 2 5% 4 4 3 3 4 5% 48%	2090
	21st to end	Night	18% 6% 1 5% 5% 4 3 3 4 6% 45%	2090
October	1st to 10th	Night	20% 7% 2 5% 3 3 3 3 5% 6% 42%	2229
	11th to 20th	Night	17% 9% 2 6% 5% 4 4 4 4 7% 38%	2280
	21st to end	Night	23% 9% 2 7% 4 3 4 3 5% 6% 34%	2650
November	1st to 10th	Night	21% 7% 3 7% 4 4 4 3 5% 6% 37%	2582
	11th to 20th	Night	20% 7% 3 7% 5% 5% 4 4 5% 5% 36%	2800
	21st to end	Night	22% 11% 3 6% 4 4 4 3 6% 6% 30%	2800
December	1st to 10th	Night	17% 11% 3 8% 5% 4 4 3 5% 6% 33%	4674
	11th to 20th	Night	23% 10% 2 6% 4 4 4 3 5% 5% 35%	5591
	21st to end	Night	20% 13% 4 9% 4 4 4 3 4 4 32%	7502

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	54% 5% 16% 16% 9%	2278
	11th to 20th	Day	53% 5% 7% 21% 11% 1	2573
	21st to end	Day	46% 7% 13% 19% 14% 1	2943
February	1st to 10th	Day	55% 5% 11% 18% 9% 2	1710
	11th to 20th	Day	57% 4 10% 17% 11% 1	1671
	21st to end	Day	50% 4 11% 22% 10% 3	1544
March	1st to 10th	Day	58% 3 9% 15% 9% 4	3265
	11th to 20th	Day	63% 5% 10% 12% 8% 2	3480
	21st to end	Day	63% 2 7% 15% 10% 2	3816
April	1st to 10th	Day	58% 3 9% 14% 13% 2	2234
	11th to 20th	Day	50% 4 11% 21% 12% 2	2442
	21st to end	Day	54% 5% 8% 16% 13% 5%	2470
May	1st to 10th	Day	53% 8% 8% 21% 9% 2	4120
	11th to 20th	Day	50% 7% 13% 21% 8% 1	4288
	21st to end	Day	48% 7% 12% 17% 15%	5049
June	1st to 10th	Day	57% 6% 10% 16% 11% 1	2850
	11th to 20th	Day	48% 5% 11% 20% 14% 1	2850
	21st to end	Day	57% 7% 9% 16% 10% 1	2850
July	1st to 10th	Day	46% 7% 16% 20% 11%	4685
	11th to 20th	Day	46% 7% 14% 24% 9%	4631
	21st to end	Day	46% 7% 12% 26% 8% 1	4491
August	1st to 10th	Day	52% 5% 12% 24% 6%	4092
	11th to 20th	Day	49% 7% 14% 23% 7%	4084
	21st to end	Day	38% 6% 13% 26% 16% 1	4532
September	1st to 10th	Day	38% 6% 13% 28% 15%	2258
	11th to 20th	Day	41% 4 9% 28% 16% 2	2090
	21st to end	Day	42% 5% 9% 27% 17% 1	2090
October	1st to 10th	Day	49% 5% 11% 26% 9%	3236
	11th to 20th	Day	44% 5% 12% 30% 9%	3140
	21st to end	Day	41% 4 15% 22% 17%	3180
November	1st to 10th	Day	51% 4 12% 20% 13% 1	1715
	11th to 20th	Day	49% 5% 14% 17% 13% 2	1600
	21st to end	Day	57% 5% 13% 19% 6%	1600
December	1st to 10th	Day	51% 5% 18% 16% 9%	2511
	11th to 20th	Day	54% 4 9% 18% 10% 4	2618
	21st to end	Day	54% 4 12% 16% 12% 3	3476
January	1st to 10th	Night	50% 5% 16% 20% 8% 1	4898
	11th to 20th	Night	52% 8% 10% 21% 9% 1	4603
	21st to end	Night	49% 6% 11% 20% 13% 1	4735
February	1st to 10th	Night	52% 5% 11% 18% 12% 1	2470
	11th to 20th	Night	55% 5% 11% 17% 11% 2	2406
	21st to end	Night	53% 5% 10% 18% 12% 3	1908
March	1st to 10th	Night	61% 4 7% 18% 9% 1	3588
	11th to 20th	Night	58% 7% 12% 14% 8% 1	3480
	21st to end	Night	61% 2 7% 17% 12% 2	3816
April	1st to 10th	Night	56% 4 8% 15% 12% 4	1942
	11th to 20th	Night	50% 3 9% 19% 16% 2	1688
	21st to end	Night	53% 5% 9% 17% 14% 3	1710
May	1st to 10th	Night	48% 9% 13% 20% 9% 1	2840
	11th to 20th	Night	47% 7% 14% 23% 7% 1	2615
	21st to end	Night	45% 8% 16% 21% 9% 1	2565
June	1st to 10th	Night	55% 6% 10% 19% 9% 1	1330
	11th to 20th	Night	47% 5% 12% 23% 11% 1	1330
	21st to end	Night	54% 6% 11% 19% 9% 1	1330
July	1st to 10th	Night	44% 7% 15% 23% 11%	2175
	11th to 20th	Night	46% 7% 15% 26% 6%	2198
	21st to end	Night	43% 9% 12% 27% 9%	2789
August	1st to 10th	Night	52% 8% 12% 21% 7%	2813
	11th to 20th	Night	44% 10% 18% 22% 6%	2809
	21st to end	Night	36% 7% 15% 23% 16% 2	3124
September	1st to 10th	Night	38% 6% 12% 29% 14% 1	1919
	11th to 20th	Night	39% 4 12% 28% 16% 1	2090
	21st to end	Night	42% 5% 9% 28% 14% 2	2090
October	1st to 10th	Night	47% 4 11% 25% 12%	3723
	11th to 20th	Night	41% 5% 12% 28% 14%	3779
	21st to end	Night	43% 5% 15% 23% 14%	4363
November	1st to 10th	Night	48% 5% 13% 22% 10% 1	2582
	11th to 20th	Night	50% 5% 12% 20% 12% 2	2800
	21st to end	Night	54% 6% 13% 15% 10% 1	2800
December	1st to 10th	Night	50% 5% 13% 24% 7%	4674
	11th to 20th	Night	51% 3 11% 21% 13% 1	5592
	21st to end	Night	56% 4 9% 18% 10% 3	7502

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	33% 17% 35% 15% 2	200
	11th to 20th	Day	33% 22% 30% 11% 4 1	200
	21st to end	Day	24% 20% 33% 18% 5% 1	298
February	1st to 10th	Day	31% 16% 32% 15% 5% 1	370
	11th to 20th	Day	31% 23% 29% 13% 3 1	366
	21st to end	Day	28% 22% 29% 18% 3	370
March	1st to 10th	Day	32% 20% 32% 12% 3	460
	11th to 20th	Day	31% 19% 31% 14% 4 2	460
	21st to end	Day	35% 18% 28% 10% 6% 2	506
April	1st to 10th	Day	41% 21% 24% 11% 3	460
	11th to 20th	Day	34% 19% 30% 12% 4 1	452
	21st to end	Day	35% 19% 29% 13% 4 1	460
May	1st to 10th	Day	35% 17% 28% 14% 5% 1	463
	11th to 20th	Day	32% 15% 28% 17% 7% 1	599
	21st to end	Day	27% 16% 35% 15% 7%	735
June	1st to 10th	Day	34% 16% 27% 16% 6% 1	680
	11th to 20th	Day	28% 14% 27% 22% 8% 1	680
	21st to end	Day	30% 12% 30% 19% 8% 1	680
July	1st to 10th	Day	24% 11% 35% 19% 10% 1	670
	11th to 20th	Day	21% 9% 33% 25% 11% 2	646
	21st to end	Day	17% 9% 39% 26% 7% 2	532
August	1st to 10th	Day	19% 11% 34% 23% 10% 2	486
	11th to 20th	Day	19% 12% 24% 30% 12% 3	479
	21st to end	Day	21% 12% 26% 26% 11% 4	539
September	1st to 10th	Day	13% 15% 34% 24% 10% 3	490
	11th to 20th	Day	24% 10% 29% 22% 11% 4	490
	21st to end	Day	22% 15% 29% 19% 10% 4	490
October	1st to 10th	Day	24% 15% 23% 24% 12% 3	415
	11th to 20th	Day	25% 18% 28% 17% 9% 3	390
	21st to end	Day	31% 18% 30% 15% 6%	429
November	1st to 10th	Day	32% 14% 29% 18% 6% 1	395
	11th to 20th	Day	35% 19% 25% 15% 6%	400
	21st to end	Day	35% 20% 27% 16% 2 1	400
December	1st to 10th	Day	34% 16% 28% 17% 4	340
	11th to 20th	Day	42% 21% 27% 10% 1	200
	21st to end	Day	30% 25% 26% 14% 3	220
January	1st to 10th	Night	28% 18% 30% 20% 3	900
	11th to 20th	Night	30% 16% 29% 21% 4	805
	21st to end	Night	21% 21% 34% 20% 5%	841
February	1st to 10th	Night	25% 21% 31% 19% 4	760
	11th to 20th	Night	28% 20% 32% 16% 3	743
	21st to end	Night	26% 18% 30% 22% 4	628
March	1st to 10th	Night	26% 18% 33% 20% 2	760
	11th to 20th	Night	25% 17% 33% 19% 5%	760
	21st to end	Night	29% 14% 32% 19% 5%	836
April	1st to 10th	Night	36% 15% 30% 17% 2	688
	11th to 20th	Night	30% 16% 31% 17% 5%	564
	21st to end	Night	33% 13% 31% 18% 6%	570
May	1st to 10th	Night	27% 14% 30% 24% 4	570
	11th to 20th	Night	31% 11% 32% 20% 6%	562
	21st to end	Night	21% 14% 36% 25% 4	509
June	1st to 10th	Night	28% 8% 31% 27% 6%	380
	11th to 20th	Night	21% 9% 29% 33% 7% 1	380
	21st to end	Night	30% 6% 27% 31% 6%	380
July	1st to 10th	Night	19% 7% 36% 29% 8%	370
	11th to 20th	Night	18% 5% 28% 36% 13%	368
	21st to end	Night	20% 7% 29% 35% 9%	495
August	1st to 10th	Night	20% 5% 27% 37% 12%	568
	11th to 20th	Night	19% 7% 28% 34% 13%	562
	21st to end	Night	16% 7% 29% 30% 16% 1	627
September	1st to 10th	Night	18% 10% 35% 27% 10% 1	622
	11th to 20th	Night	20% 8% 24% 31% 14% 2	760
	21st to end	Night	22% 12% 27% 28% 11% 1	760
October	1st to 10th	Night	23% 10% 28% 28% 10% 1	760
	11th to 20th	Night	22% 14% 29% 25% 9% 1	760
	21st to end	Night	29% 15% 30% 21% 5%	836
November	1st to 10th	Night	28% 15% 29% 23% 5% 1	803
	11th to 20th	Night	31% 16% 28% 18% 7% 1	900
	21st to end	Night	32% 17% 27% 20% 4	900
December	1st to 10th	Night	33% 14% 29% 19% 4	900
	11th to 20th	Night	32% 20% 28% 17% 3	900
	21st to end	Night	32% 19% 27% 18% 4 1	990

Page generated at 2025-01-19 04:06:46. Version ac07

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