Anoka-Ramsey Community College (Cambridge)
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Anoka-Ramsey Community College (Cambridge) clear sky chart from 2005-11-05 to 2018-01-12.

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 TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(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

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
34%
16676
14%
48162
8%
16629
39%
16629
24%
32494

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
30%
956
13%
2662
7%
951
35%
951
22%
1886
January16th to endNight
21%
960
10%
2562
4%
960
26%
960
17%
1946
February1st to 15thNight
28%
879
13%
2288
4%
875
33%
875
24%
1600
February16th to endNight
30%
757
12%
2019
4%
757
35%
757
22%
1438
March1st to 15thNight
30%
586
13%
2026
9%
586
35%
586
19%
1351
March16th to endNight
28%
576
16%
2094
12%
576
36%
576
17%
1410
April1st to 15thNight
28%
539
14%
1797
11%
539
35%
539
21%
1182
April16th to endNight
26%
540
13%
1662
8%
540
33%
540
18%
1198
May1st to 15thNight
27%
540
13%
1482
5%
540
33%
540
24%
1043
May16th to endNight
37%
563
11%
1498
4%
561
40%
561
29%
994
June1st to 15thNight
40%
540
9%
1440
3%
540
43%
540
32%
923
June16th to endNight
47%
540
13%
1272
6%
540
50%
540
41%
807
July1st to 15thNight
54%
510
14%
1284
6%
510
56%
510
43%
789
July16th to endNight
55%
564
17%
1417
9%
531
61%
531
44%
814
August1st to 15thNight
62%
539
20%
1608
18%
536
65%
536
37%
916
August16th to endNight
53%
573
20%
1786
18%
573
59%
573
35%
1034
September1st to 15thNight
52%
540
21%
1800
19%
540
60%
540
37%
962
September16th to endNight
43%
585
19%
1982
14%
585
51%
585
29%
1155
October1st to 15thNight
38%
720
21%
2160
13%
720
43%
720
31%
1301
October16th to endNight
32%
768
15%
2329
9%
768
37%
768
20%
1593
November1st to 15thNight
29%
911
17%
2622
10%
911
36%
911
22%
1775
November16th to endNight
26%
975
14%
2730
8%
975
32%
975
19%
1965
December1st to 15thNight
21%
975
9%
2730
3%
975
26%
975
16%
2094
December16th to endNight
19%
1040
10%
2912
3%
1040
25%
1040
13%
2318

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 ForecastData
Points
Cloud CoverDay
14%7%36%5%3445%7%36%
49173
Night
13%8%36%5%24446%40%
48328
Cloud CoverDay
25%7%25%5%23446%32%
49184
Night
24%7%25%423345%35%
48332
Cloud CoverDay
13%8%36%5%3445%7%36%
49182
Night
13%8%36%5%2445%6%39%
48332
TransparencyDay
46%6%13%23%9%
48858
Night
44%5%13%23%11%1
48162
SeeingDay
16%6%28%28%15%4
6505
Night
16%6%30%32%12%1
16677

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
10%9%6%7%7%37%45%7%29%
1520
16th to endDay
10%13%6%10%6%346%6%7%24%
1659
February1st to 15thDay
8%11%6%9%7%35%347%32%
1575
16th to endDay
10%11%5%8%7%35%5%47%31%
1452
March1st to 15thDay
14%8%47%5%35%35%7%33%
1933
16th to endDay
19%9%36%32445%6%32%
2130
April1st to 15thDay
17%9%25%5%34345%37%
2151
16th to endDay
23%10%36%5%34346%29%
2295
May1st to 15thDay
20%8%36%6%45%445%30%
2469
16th to endDay
14%6%25%6%3445%8%36%
2617
June1st to 15thDay
16%6%25%42445%8%39%
2520
16th to endDay
10%425%5%35%5%7%9%40%
2682
July1st to 15thDay
6%4244245%6%8%51%
2595
16th to endDay
7%3144345%6%10%48%
2655
August1st to 15thDay
8%425%5%25%6%7%9%42%
2340
16th to endDay
14%5%23323448%46%
2415
September1st to 15thDay
8%425%5%345%6%8%46%
2160
16th to endDay
16%42442445%7%41%
1965
October1st to 15thDay
17%7%345%23446%41%
1800
16th to endDay
20%9%35%5%2334436%
1893
November1st to 15thDay
14%11%37%5%2445%5%34%
1563
16th to endDay
15%11%36%5%345%6%7%30%
1560
December1st to 15thDay
16%12%7%7%8%45%45%5%23%
1560
16th to endDay
16%16%8%10%5%3433422%
1664
January1st to 15thNight
10%8%5%8%5%3445%7%34%
2662
16th to endNight
12%13%6%10%5%24446%29%
2562
February1st to 15thNight
7%11%48%5%3445%6%38%
2285
16th to endNight
9%9%47%6%46%446%36%
2019
March1st to 15thNight
12%9%36%6%34436%39%
2014
16th to endNight
17%8%45%6%13446%36%
2094
April1st to 15thNight
18%9%36%413335%39%
1797
16th to endNight
24%7%4441445%5%33%
1662
May1st to 15thNight
19%6%25%423446%39%
1482
16th to endNight
12%425%5%26%5%5%7%42%
1496
June1st to 15thNight
12%4245%2346%8%45%
1440
16th to endNight
9%315%32345%9%51%
1272
July1st to 15thNight
5%1144245%5%8%54%
1362
16th to endNight
5%2134245%6%9%55%
1513
August1st to 15thNight
9%315%42335%8%53%
1617
16th to endNight
10%424413346%53%
1786
September1st to 15thNight
8%32442345%6%55%
1800
16th to endNight
13%32432345%7%49%
1982
October1st to 15thNight
14%6%23322346%49%
2160
16th to endNight
19%8%35%423346%38%
2329
November1st to 15thNight
15%9%36%424345%40%
2622
16th to endNight
15%8%46%6%3435%6%34%
2730
December1st to 15thNight
13%13%5%9%6%34435%29%
2730
16th to endNight
16%15%5%10%7%25%35%5%23%
2912

Percentage Cloud Cover SW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
22%7%46%6%35%45%6%26%
1520
16th to endDay
24%12%48%6%335%5%6%19%
1659
February1st to 15thDay
23%10%47%6%24236%28%
1575
16th to endDay
23%9%37%7%34435%27%
1452
March1st to 15thDay
26%7%26%434345%29%
1944
16th to endDay
31%8%26%323345%27%
2130
April1st to 15thDay
30%7%245%2333431%
2151
16th to endDay
36%9%25%42333423%
2295
May1st to 15thDay
32%7%26%6%3433425%
2469
16th to endDay
29%5%245%24345%30%
2617
June1st to 15thDay
30%5%2442345%6%31%
2520
16th to endDay
25%31443445%8%33%
2682
July1st to 15thDay
22%41332335%6%42%
2595
16th to endDay
23%21342345%8%38%
2655
August1st to 15thDay
16%414435%6%7%8%38%
2340
16th to endDay
20%414323447%43%
2415
September1st to 15thDay
16%3144245%5%7%43%
2160
16th to endDay
21%41433345%7%40%
1965
October1st to 15thDay
24%6%25%5%22345%37%
1800
16th to endDay
26%7%25%423335%35%
1893
November1st to 15thDay
24%9%26%42344432%
1563
16th to endDay
27%10%25%6%24445%26%
1560
December1st to 15thDay
28%11%5%7%7%3434420%
1560
16th to endDay
27%14%7%9%44322419%
1664
January1st to 15thNight
22%7%37%5%23346%31%
2662
16th to endNight
26%12%5%9%423345%24%
2562
February1st to 15thNight
23%10%36%423345%32%
2278
16th to endNight
21%8%26%6%35%435%31%
2019
March1st to 15thNight
25%8%25%5%23335%34%
2026
16th to endNight
31%7%3442233433%
2094
April1st to 15thNight
31%7%25%31333433%
1797
16th to endNight
37%7%3431334426%
1662
May1st to 15thNight
31%6%25%322435%33%
1481
16th to endNight
27%41442445%5%34%
1496
June1st to 15thNight
26%315%322346%38%
1440
16th to endNight
23%314322347%43%
1272
July1st to 15thNight
21%21332345%6%45%
1362
16th to endNight
21%212323447%46%
1513
August1st to 15thNight
16%21442235%7%49%
1617
16th to endNight
17%314412246%50%
1786
September1st to 15thNight
15%314323446%51%
1800
16th to endNight
19%313313346%47%
1982
October1st to 15thNight
21%6%14322246%45%
2160
16th to endNight
25%7%26%423336%35%
2329
November1st to 15thNight
25%7%25%31333436%
2622
16th to endNight
26%7%35%5%3334430%
2730
December1st to 15thNight
26%11%48%5%3333425%
2730
16th to endNight
27%14%49%6%2333420%
2912

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
10%9%6%8%7%36%46%6%30%
1520
16th to endDay
10%13%6%11%6%35%6%6%6%23%
1659
February1st to 15thDay
8%10%6%9%7%35%347%33%
1575
16th to endDay
10%11%48%7%35%446%31%
1452
March1st to 15thDay
13%9%46%6%34446%33%
1944
16th to endDay
18%10%36%424446%31%
2128
April1st to 15thDay
16%9%36%5%24345%37%
2151
16th to endDay
23%9%36%5%34445%29%
2295
May1st to 15thDay
19%8%37%6%445%45%30%
2469
16th to endDay
14%7%35%6%3445%7%35%
2617
June1st to 15thDay
15%6%25%5%3446%8%38%
2520
16th to endDay
10%4246%45%5%7%9%39%
2682
July1st to 15thDay
6%4245%2446%9%50%
2595
16th to endDay
6%4144345%6%10%47%
2655
August1st to 15thDay
8%3246%35%6%7%9%41%
2340
16th to endDay
13%42432345%7%46%
2415
September1st to 15thDay
8%4245%3447%8%46%
2160
16th to endDay
15%6%245%335%47%41%
1965
October1st to 15thDay
16%8%25%423446%40%
1800
16th to endDay
21%8%35%5%23435%36%
1893
November1st to 15thDay
14%11%47%5%3445%5%34%
1563
16th to endDay
15%11%26%6%35%5%6%6%29%
1560
December1st to 15thDay
16%11%8%7%8%445%5%5%22%
1560
16th to endDay
16%15%8%11%5%4343421%
1664
January1st to 15thNight
11%8%48%5%2445%7%34%
2662
16th to endNight
11%14%5%10%5%24446%28%
2562
February1st to 15thNight
7%11%48%5%2445%6%37%
2278
16th to endNight
9%9%46%8%36%446%36%
2019
March1st to 15thNight
12%9%37%6%24346%39%
2026
16th to endNight
17%9%35%6%23346%35%
2094
April1st to 15thNight
18%9%45%423335%39%
1797
16th to endNight
23%8%35%32345%433%
1662
May1st to 15thNight
18%7%36%324446%38%
1481
16th to endNight
11%5%25%5%36%47%7%41%
1496
June1st to 15thNight
12%425%43346%7%44%
1440
16th to endNight
8%4244243410%50%
1272
July1st to 15thNight
43144245%6%8%54%
1362
16th to endNight
42134245%6%9%54%
1513
August1st to 15thNight
8%32442345%7%53%
1617
16th to endNight
11%424323336%53%
1786
September1st to 15thNight
7%32432345%6%55%
1800
16th to endNight
13%424424347%48%
1982
October1st to 15thNight
14%6%24322346%48%
2160
16th to endNight
19%9%26%5%23345%37%
2329
November1st to 15thNight
14%9%36%5%2445%5%39%
2622
16th to endNight
15%8%47%6%34447%33%
2730
December1st to 15thNight
13%13%5%9%7%34445%28%
2730
16th to endNight
15%16%5%10%7%3445%5%22%
2912

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
51%7%12%20%7%
1521
16th to endDay
57%7%15%14%4
1659
February1st to 15thDay
51%5%13%21%6%1
1576
16th to endDay
53%6%11%21%6%
1452
March1st to 15thDay
50%5%17%19%6%
1944
16th to endDay
52%5%12%23%3
2130
April1st to 15thDay
48%411%20%13%1
2151
16th to endDay
56%5%10%16%9%
2295
May1st to 15thDay
55%6%10%19%7%
2469
16th to endDay
45%7%11%22%11%1
2621
June1st to 15thDay
41%7%14%27%7%
2520
16th to endDay
37%7%16%26%9%1
2682
July1st to 15thDay
29%7%14%30%16%1
2444
16th to endDay
30%8%17%26%15%1
2488
August1st to 15thDay
35%10%13%28%10%1
2326
16th to endDay
35%5%16%27%13%1
2415
September1st to 15thDay
32%8%14%34%9%
2160
16th to endDay
40%7%12%31%6%
1965
October1st to 15thDay
44%5%12%24%11%
1800
16th to endDay
49%5%14%21%8%
1893
November1st to 15thDay
49%5%12%20%11%
1563
16th to endDay
51%8%18%15%5%1
1560
December1st to 15thDay
62%6%12%14%4
1560
16th to endDay
67%5%9%11%6%
1664
January1st to 15thNight
47%6%12%22%9%
2662
16th to endNight
56%414%17%5%
2562
February1st to 15thNight
45%5%15%24%7%
2288
16th to endNight
47%6%14%22%8%
2019
March1st to 15thNight
47%6%14%21%9%
2026
16th to endNight
49%5%13%24%6%
2094
April1st to 15thNight
46%49%23%14%1
1797
16th to endNight
51%7%8%18%12%2
1662
May1st to 15thNight
46%6%14%19%12%1
1482
16th to endNight
39%6%14%22%14%2
1498
June1st to 15thNight
35%7%14%28%11%2
1440
16th to endNight
28%8%13%30%15%4
1272
July1st to 15thNight
26%8%14%31%17%2
1284
16th to endNight
22%9%14%30%19%4
1417
August1st to 15thNight
29%5%12%32%14%4
1608
16th to endNight
31%5%13%29%15%3
1786
September1st to 15thNight
27%5%14%35%16%
1800
16th to endNight
34%5%14%32%12%
1982
October1st to 15thNight
36%411%31%14%1
2160
16th to endNight
48%5%12%21%11%
2329
November1st to 15thNight
46%412%23%12%
2622
16th to endNight
49%6%16%17%8%1
2730
December1st to 15thNight
57%5%13%17%4
2730
16th to endNight
63%411%12%6%
2912

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
17%8%31%28%10%2
123
16th to endDay
20%9%33%26%9%1
96
February1st to 15thDay
14%13%44%24%3
90
16th to endDay
23%11%35%22%6%1
81
March1st to 15thDay
20%6%32%31%8%1
90
16th to endDay
30%9%22%26%10%
114
April1st to 15thDay
21%9%28%27%11%1
270
16th to endDay
30%6%31%19%10%1
405
May1st to 15thDay
21%10%30%26%8%2
468
16th to endDay
20%6%30%21%14%5%
517
June1st to 15thDay
15%5%28%32%15%2
495
16th to endDay
10%431%31%15%5%
495
July1st to 15thDay
8%423%29%24%10%
475
16th to endDay
9%223%35%22%7%
515
August1st to 15thDay
10%120%34%26%6%
493
16th to endDay
16%319%32%19%7%
455
September1st to 15thDay
8%327%32%22%5%
315
16th to endDay
21%6%26%30%10%5%
180
October1st to 15thDay
14%8%36%19%14%7%
135
16th to endDay
23%9%33%20%12%
144
November1st to 15thDay
14%11%28%28%15%1
135
16th to endDay
28%9%37%20%4
135
December1st to 15thDay
20%8%33%29%7%
135
16th to endDay
27%9%39%21%2
144
January1st to 15thNight
15%8%33%31%9%2
956
16th to endNight
18%7%37%28%7%
960
February1st to 15thNight
13%8%35%31%10%1
880
16th to endNight
13%8%36%28%11%
757
March1st to 15thNight
16%8%34%30%9%
586
16th to endNight
21%7%30%27%11%2
576
April1st to 15thNight
22%7%32%29%7%
539
16th to endNight
27%430%26%9%1
540
May1st to 15thNight
19%9%32%29%8%
540
16th to endNight
13%6%28%34%15%1
563
June1st to 15thNight
13%227%43%12%
540
16th to endNight
10%422%43%18%
540
July1st to 15thNight
6%123%43%23%1
510
16th to endNight
6%119%46%24%1
564
August1st to 15thNight
11%112%47%25%2
539
16th to endNight
13%20%38%25%1
573
September1st to 15thNight
9%222%39%22%4
540
16th to endNight
13%5%30%28%19%1
585
October1st to 15thNight
19%6%29%30%13%1
720
16th to endNight
23%7%28%31%8%
768
November1st to 15thNight
18%9%31%30%9%
911
16th to endNight
19%10%32%27%9%
975
December1st to 15thNight
18%9%36%29%6%
975
16th to endNight
22%7%31%28%8%
1040
Page generated at 2018-01-12 21:01:36. Version ac04

Copyright 2018 A. Danko


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