Hi Brianna,

Thanks for the pictures of your cucumber plants. It looks like Anthracnose fungus is affecting your plants. The fungi may have bloomed as a result of the hot humid weather we're experiencing. Attached is some links describing this fungi in more detail. 

https://ag.umass.edu/vegetable/fact-sheets/cucurbits-anthracnose

https://portal.ct.gov/-/media/caes/documents/publications/fact_sheets/plant_pathology_and_ecology/anthracnoseofcucumber013014pdf.pdf 

You could try a fungicide to aid in controlling this disease. There are some organic options including potassium bicarbonate, coppers, Bacillus sibtilis and some horticultural oils that may be available at your local garden supply. Please read and follow the label directions carefully if you choose to go this route. Here is some more information about options:

https://www.extension.purdue.edu/extmedia/bp/bp-69-w.pdf

Two things to note for future cucumber growing is that there are certified disease-free seeds available and the seed packages are clearly marked. Rotating your crops in future seasons, i.e. not putting cucumbers in the same spot in your garden for at least 2 seasons, will help to prevent having this problem going forward.

I hope this information helps. Please feel free to follow up with any additional questions.

Cyndy