Port Crescent State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Port Crescent State Park clear sky chart from 2005-11-06 to 2024-02-20.

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% 10% 4 7% 6% 4 5% 5% 5% 7% 33%	78129
	Night	15% 11% 5% 9% 7% 4 5% 4 5% 6% 29%	81088
Transparency	Day	51% 4 12% 21% 11% 1	77834
	Night	55% 4 11% 19% 9% 1	80904
Seeing	Day	18% 9% 29% 26% 13% 5%	14341
	Night	20% 9% 29% 28% 12% 2	24027

By Month

Percentage Cloud Cover SE (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	16% 16% 11% 15% 8% 4 6% 4 4 4 14%	2527
	11th to 20th	Day	13% 17% 9% 16% 16% 7% 4 3 4 4 7%	2530
	21st to end	Day	21% 16% 7% 11% 9% 4 5% 4 5% 5% 14%	2970
February	1st to 10th	Day	12% 15% 5% 11% 9% 4 5% 5% 5% 6% 21%	1710
	11th to 20th	Day	11% 12% 6% 9% 10% 6% 5% 6% 5% 6% 24%	1733
	21st to end	Day	14% 11% 4 8% 6% 4 5% 5% 6% 8% 27%	1480
March	1st to 10th	Day	13% 10% 5% 9% 8% 4 6% 5% 5% 6% 29%	1843
	11th to 20th	Day	11% 9% 5% 10% 6% 5% 5% 6% 6% 6% 31%	1980
	21st to end	Day	16% 10% 5% 8% 7% 4 4 4 5% 7% 30%	2178
April	1st to 10th	Day	16% 10% 4 7% 6% 3 4 5% 6% 8% 31%	2091
	11th to 20th	Day	16% 8% 3 5% 5% 3 4 5% 5% 7% 38%	2312
	21st to end	Day	15% 8% 4 6% 6% 4 5% 4 5% 7% 36%	2340
May	1st to 10th	Day	14% 7% 2 6% 6% 3 4 5% 6% 7% 39%	2340
	11th to 20th	Day	14% 6% 3 7% 6% 3 5% 5% 5% 6% 41%	2301
	21st to end	Day	11% 6% 2 5% 5% 2 4 5% 5% 9% 46%	2694
June	1st to 10th	Day	10% 6% 2 4 5% 3 5% 6% 6% 8% 44%	2700
	11th to 20th	Day	10% 4 2 5% 5% 3 5% 6% 6% 9% 45%	2700
	21st to end	Day	10% 5% 3 4 5% 3 4 6% 6% 9% 45%	2700
July	1st to 10th	Day	7% 4 2 3 3 2 4 4 7% 10% 53%	2612
	11th to 20th	Day	8% 4 2 5% 6% 3 4 4 7% 9% 48%	2520
	21st to end	Day	8% 3 2 5% 5% 3 5% 5% 7% 10% 47%	2646
August	1st to 10th	Day	9% 5% 2 5% 5% 3 5% 5% 6% 9% 45%	2327
	11th to 20th	Day	9% 4 2 5% 4 3 5% 5% 6% 9% 48%	2303
	21st to end	Day	12% 6% 3 5% 4 2 4 5% 6% 8% 46%	2574
September	1st to 10th	Day	11% 5% 2 6% 5% 3 5% 4 6% 8% 43%	2063
	11th to 20th	Day	14% 6% 2 5% 4 3 3 4 6% 8% 45%	1980
	21st to end	Day	15% 7% 3 5% 6% 4 5% 6% 6% 7% 37%	1980
October	1st to 10th	Day	17% 8% 3 6% 6% 3 4 4 5% 7% 37%	1905
	11th to 20th	Day	22% 11% 4 7% 6% 3 5% 5% 4 7% 26%	1800
	21st to end	Day	24% 12% 4 8% 6% 4 5% 5% 5% 6% 21%	1820
November	1st to 10th	Day	14% 13% 4 9% 6% 4 6% 4 6% 7% 28%	1672
	11th to 20th	Day	15% 16% 5% 8% 8% 4 5% 5% 6% 7% 21%	1652
	21st to end	Day	17% 19% 6% 12% 7% 4 4 4 5% 5% 17%	1520
December	1st to 10th	Day	13% 21% 10% 12% 10% 5% 6% 4 4 4 12%	1511
	11th to 20th	Day	15% 16% 7% 12% 9% 4 5% 5% 4 6% 17%	1675
	21st to end	Day	25% 22% 8% 11% 7% 4 4 4 3 4 8%	2440
January	1st to 10th	Night	17% 14% 9% 15% 9% 4 4 4 4 5% 17%	4428
	11th to 20th	Night	13% 15% 9% 16% 17% 7% 5% 3 3 3 9%	4440
	21st to end	Night	17% 15% 8% 12% 10% 5% 6% 5% 5% 4 13%	4688
February	1st to 10th	Night	13% 14% 6% 11% 8% 4 6% 5% 5% 7% 21%	2470
	11th to 20th	Night	14% 13% 6% 10% 7% 4 5% 4 5% 7% 26%	2317
	21st to end	Night	16% 13% 5% 9% 7% 4 5% 5% 4 6% 26%	1776
March	1st to 10th	Night	12% 12% 5% 7% 7% 3 5% 4 4 6% 36%	2116
	11th to 20th	Night	12% 10% 4 8% 6% 4 4 5% 4 6% 36%	1980
	21st to end	Night	18% 12% 5% 7% 6% 3 5% 3 4 5% 33%	2178
April	1st to 10th	Night	18% 11% 4 6% 5% 2 4 4 4 7% 34%	1885
	11th to 20th	Night	17% 7% 2 5% 5% 3 5% 4 5% 8% 38%	1597
	21st to end	Night	18% 8% 4 7% 6% 3 3 4 5% 7% 35%	1620
May	1st to 10th	Night	11% 8% 3 7% 6% 4 6% 5% 5% 9% 36%	1620
	11th to 20th	Night	16% 6% 3 6% 5% 4 5% 4 6% 7% 38%	1592
	21st to end	Night	11% 4 2 5% 4 3 5% 5% 6% 9% 47%	1575
June	1st to 10th	Night	14% 5% 3 6% 6% 2 3 5% 5% 7% 43%	1260
	11th to 20th	Night	10% 5% 2 5% 5% 4 5% 5% 6% 9% 45%	1260
	21st to end	Night	9% 6% 3 6% 5% 3 5% 5% 5% 9% 44%	1260
July	1st to 10th	Night	6% 4 2 4 4 3 4 4 6% 9% 55%	1342
	11th to 20th	Night	8% 5% 1 4 5% 3 5% 5% 6% 10% 48%	1440
	21st to end	Night	8% 4 2 7% 5% 3 4 6% 6% 8% 48%	1669
August	1st to 10th	Night	8% 4 2 4 5% 4 4 6% 6% 10% 47%	1611
	11th to 20th	Night	8% 4 2 5% 4 3 4 5% 7% 10% 49%	1598
	21st to end	Night	11% 5% 2 6% 5% 3 4 4 7% 8% 45%	1782
September	1st to 10th	Night	11% 6% 3 5% 5% 3 5% 4 5% 7% 45%	1876
	11th to 20th	Night	12% 6% 2 5% 5% 3 4 4 5% 6% 49%	1980
	21st to end	Night	15% 7% 4 6% 6% 3 4 4 5% 7% 40%	1980
October	1st to 10th	Night	17% 7% 3 6% 6% 3 5% 5% 5% 7% 37%	2054
	11th to 20th	Night	22% 12% 4 7% 6% 4 3 4 4 6% 28%	2160
	21st to end	Night	25% 13% 4 8% 6% 3 4 5% 4 5% 23%	2533
November	1st to 10th	Night	15% 13% 4 7% 5% 3 5% 5% 4 6% 32%	2406
	11th to 20th	Night	15% 15% 6% 12% 8% 4 5% 5% 5% 5% 20%	2527
	21st to end	Night	21% 17% 6% 11% 7% 4 4 4 4 4 18%	2660
December	1st to 10th	Night	19% 18% 9% 12% 8% 3 5% 4 4 6% 14%	2664
	11th to 20th	Night	14% 15% 7% 14% 9% 5% 6% 5% 5% 7% 14%	3522
	21st to end	Night	24% 21% 9% 10% 7% 4 5% 4 3 4 9%	5222

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	72% 4 11% 9% 3	2528
	11th to 20th	Day	82% 4 5% 7% 2	2530
	21st to end	Day	73% 3 13% 8% 3	2970
February	1st to 10th	Day	62% 5% 10% 18% 5%	1710
	11th to 20th	Day	61% 4 11% 16% 8% 1	1742
	21st to end	Day	56% 4 11% 20% 8% 1	1480
March	1st to 10th	Day	57% 3 13% 16% 10% 1	1843
	11th to 20th	Day	53% 4 11% 20% 9% 3	1980
	21st to end	Day	56% 3 11% 21% 8% 1	2178
April	1st to 10th	Day	53% 3 13% 19% 11% 1	2091
	11th to 20th	Day	47% 3 12% 22% 15% 2	2312
	21st to end	Day	49% 3 14% 19% 13% 2	2340
May	1st to 10th	Day	45% 3 10% 26% 13% 2	2340
	11th to 20th	Day	45% 3 10% 24% 15% 3	2305
	21st to end	Day	37% 4 15% 26% 15% 3	2694
June	1st to 10th	Day	37% 5% 14% 27% 17% 1	2700
	11th to 20th	Day	35% 4 13% 28% 18% 2	2700
	21st to end	Day	36% 5% 13% 28% 16% 1	2700
July	1st to 10th	Day	27% 4 14% 31% 20% 3	2542
	11th to 20th	Day	34% 4 14% 31% 16% 2	2445
	21st to end	Day	34% 4 14% 28% 17% 3	2499
August	1st to 10th	Day	35% 4 16% 31% 12% 2	2314
	11th to 20th	Day	34% 4 17% 31% 13% 2	2303
	21st to end	Day	37% 4 13% 30% 14% 1	2574
September	1st to 10th	Day	40% 5% 14% 29% 11% 1	2063
	11th to 20th	Day	38% 4 14% 32% 12%	1980
	21st to end	Day	46% 4 15% 25% 9%	1980
October	1st to 10th	Day	48% 3 10% 25% 11% 2	1905
	11th to 20th	Day	58% 4 12% 19% 6%	1800
	21st to end	Day	63% 5% 12% 15% 5% 1	1820
November	1st to 10th	Day	55% 4 11% 21% 9% 1	1672
	11th to 20th	Day	61% 5% 14% 12% 8%	1652
	21st to end	Day	69% 3 11% 13% 3	1520
December	1st to 10th	Day	74% 4 11% 10% 2	1511
	11th to 20th	Day	68% 4 11% 14% 3	1671
	21st to end	Day	82% 2 7% 7% 1	2440
January	1st to 10th	Night	67% 4 11% 14% 4	4428
	11th to 20th	Night	77% 3 9% 9% 3	4440
	21st to end	Night	71% 5% 10% 11% 3	4688
February	1st to 10th	Night	62% 4 9% 18% 6% 1	2470
	11th to 20th	Night	58% 5% 11% 19% 7% 1	2319
	21st to end	Night	60% 3 10% 17% 9%	1776
March	1st to 10th	Night	51% 4 11% 25% 9% 1	2116
	11th to 20th	Night	50% 3 11% 21% 13% 2	1980
	21st to end	Night	55% 2 9% 22% 11% 1	2178
April	1st to 10th	Night	51% 3 8% 22% 14% 2	1885
	11th to 20th	Night	44% 3 10% 22% 19% 2	1597
	21st to end	Night	49% 3 8% 20% 16% 3	1620
May	1st to 10th	Night	46% 3 10% 24% 15% 2	1620
	11th to 20th	Night	45% 4 8% 22% 17% 4	1593
	21st to end	Night	35% 3 12% 29% 16% 5%	1576
June	1st to 10th	Night	41% 3 9% 28% 17% 2	1260
	11th to 20th	Night	36% 5% 13% 22% 22% 3	1260
	21st to end	Night	37% 3 13% 25% 20% 2	1260
July	1st to 10th	Night	28% 3 11% 29% 23% 4	1303
	11th to 20th	Night	31% 5% 16% 29% 18% 1	1392
	21st to end	Night	34% 5% 16% 26% 16% 2	1576
August	1st to 10th	Night	32% 4 16% 33% 13% 1	1600
	11th to 20th	Night	30% 4 15% 32% 16% 2	1598
	21st to end	Night	36% 4 13% 30% 15% 2	1782
September	1st to 10th	Night	38% 5% 11% 29% 15% 1	1876
	11th to 20th	Night	36% 3 11% 35% 15%	1980
	21st to end	Night	44% 3 12% 31% 10% 1	1980
October	1st to 10th	Night	45% 4 11% 24% 14% 1	2054
	11th to 20th	Night	58% 3 10% 22% 7% 1	2160
	21st to end	Night	62% 3 10% 18% 7%	2533
November	1st to 10th	Night	51% 4 10% 23% 10% 1	2406
	11th to 20th	Night	64% 4 12% 15% 5% 1	2527
	21st to end	Night	67% 4 13% 13% 3	2660
December	1st to 10th	Night	70% 3 10% 13% 4	2664
	11th to 20th	Night	68% 4 13% 11% 3	3525
	21st to end	Night	78% 3 10% 6% 2	5222

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	20% 14% 41% 17% 7% 1	270
	11th to 20th	Day	21% 16% 38% 19% 6% 1	270
	21st to end	Day	25% 9% 38% 22% 5% 1	297
February	1st to 10th	Day	20% 20% 39% 16% 4 1	270
	11th to 20th	Day	19% 21% 43% 15% 2	267
	21st to end	Day	23% 27% 34% 14% 3	198
March	1st to 10th	Day	22% 19% 37% 17% 4 1	283
	11th to 20th	Day	19% 16% 32% 24% 7% 2	420
	21st to end	Day	27% 10% 31% 23% 7% 1	462
April	1st to 10th	Day	22% 12% 35% 22% 7% 1	420
	11th to 20th	Day	27% 11% 28% 18% 12% 4	412
	21st to end	Day	24% 8% 34% 22% 9% 3	420
May	1st to 10th	Day	20% 11% 33% 24% 10% 3	423
	11th to 20th	Day	17% 7% 30% 24% 15% 7%	447
	21st to end	Day	14% 5% 26% 31% 17% 7%	547
June	1st to 10th	Day	13% 6% 32% 30% 15% 4	630
	11th to 20th	Day	13% 6% 29% 33% 15% 4	630
	21st to end	Day	14% 4 30% 31% 16% 5%	630
July	1st to 10th	Day	9% 3 23% 32% 24% 9%	621
	11th to 20th	Day	13% 4 24% 35% 18% 7%	618
	21st to end	Day	10% 2 24% 36% 19% 8%	587
August	1st to 10th	Day	13% 3 18% 30% 23% 13%	446
	11th to 20th	Day	10% 2 16% 32% 25% 14%	439
	21st to end	Day	17% 4 19% 30% 23% 8%	495
September	1st to 10th	Day	14% 4 25% 30% 18% 10%	450
	11th to 20th	Day	14% 4 19% 26% 23% 14%	450
	21st to end	Day	18% 6% 26% 22% 20% 9%	450
October	1st to 10th	Day	24% 7% 24% 22% 16% 6%	450
	11th to 20th	Day	29% 12% 28% 25% 5% 1	450
	21st to end	Day	32% 12% 32% 18% 5% 1	335
November	1st to 10th	Day	21% 14% 36% 20% 7% 2	270
	11th to 20th	Day	21% 18% 34% 19% 6% 2	242
	21st to end	Day	23% 18% 34% 21% 4	180
December	1st to 10th	Day	24% 14% 38% 19% 4	180
	11th to 20th	Day	27% 20% 34% 14% 3 1	180
	21st to end	Day	30% 15% 35% 15% 4	202
January	1st to 10th	Night	23% 13% 35% 22% 6% 1	950
	11th to 20th	Night	22% 15% 35% 21% 6% 1	950
	21st to end	Night	18% 9% 37% 26% 9%	927
February	1st to 10th	Night	22% 14% 37% 23% 4	760
	11th to 20th	Night	22% 13% 35% 23% 7%	742
	21st to end	Night	23% 15% 37% 21% 4	592
March	1st to 10th	Night	18% 11% 34% 27% 9% 1	720
	11th to 20th	Night	18% 12% 38% 25% 7% 1	720
	21st to end	Night	24% 10% 28% 27% 9% 1	792
April	1st to 10th	Night	23% 11% 35% 22% 8%	625
	11th to 20th	Night	22% 9% 31% 24% 12% 2	533
	21st to end	Night	23% 8% 24% 34% 10% 1	540
May	1st to 10th	Night	17% 4 28% 38% 11% 2	540
	11th to 20th	Night	18% 6% 22% 35% 17% 1	531
	21st to end	Night	13% 2 28% 35% 21% 1	482
June	1st to 10th	Night	15% 5% 24% 37% 18% 1	360
	11th to 20th	Night	14% 3 26% 39% 18% 1	360
	21st to end	Night	13% 3 24% 37% 21% 2	360
July	1st to 10th	Night	9% 1 18% 44% 27% 1	428
	11th to 20th	Night	11% 2 17% 38% 26% 5%	522
	21st to end	Night	9% 1 19% 45% 23% 3	591
August	1st to 10th	Night	10% 1 12% 41% 32% 3	537
	11th to 20th	Night	11% 2 14% 32% 33% 7%	534
	21st to end	Night	14% 3 19% 35% 26% 4	594
September	1st to 10th	Night	14% 3 21% 32% 23% 6%	646
	11th to 20th	Night	14% 3 18% 35% 23% 7%	720
	21st to end	Night	18% 7% 19% 32% 18% 7%	720
October	1st to 10th	Night	21% 7% 25% 28% 17% 2	720
	11th to 20th	Night	28% 11% 26% 27% 7% 1	720
	21st to end	Night	32% 8% 28% 27% 4 1	792
November	1st to 10th	Night	23% 13% 28% 25% 11% 1	740
	11th to 20th	Night	23% 15% 33% 21% 8%	760
	21st to end	Night	29% 14% 31% 22% 4	760
December	1st to 10th	Night	26% 15% 35% 18% 6%	764
	11th to 20th	Night	24% 15% 36% 19% 4 1	950
	21st to end	Night	29% 13% 34% 21% 3	1045

Page generated at 2024-02-17 06:28:37. Version ac07

Copyright 2024 Attilla Danko