Diener and Diener's "Most People Are Happy" (1996) summarizes the results of various studies on how happy people are, and finds that the vast majority of people are happy, based on a variety of methodologies.
Abstract:
Myers and Diener (1995) asked “Who is happy?” but examined the question of who is more and who is less happy. In fact, most people report a positive level of subjective well-being (SWB), and say that they are satisfied with domains such as marriage, work, and leisure. People in disadvantaged groups on average report positive well-being, and measurement methods in addition to self-report indicate that most people's affect is primarily pleasant. Cross-national data suggest that there is a positive level of SWB throughout the world, with the possible exception of very poor societies. In 86% of the 43 nations for which nationally representative samples are available the mean SWB response was above neutral. Several hypotheses to explain the positive levels of SWB are discussed.
Here's the section on experience sampling:
In two other studies (Thomas & Diener, 1990), college students who were "beeped" reported more positive affect than negative affect on about 80% of occasions. Similarly, Williams, Suls, Alliger, Learner, and Choi (1991) found that working mothers who were signaled at random times reported very high levels of positive affect and low levels of negative affect. Larson (1989) used the beeper methodology with American children; they reported predominantly positive affect about 52% of the time, neutral or mixed affect on about 29% of the occasions, and dominant negative affect 19% of the time.
Brandstatter (1991) drew his respondents in Europe from unemployed persons, soldiers, students, married couples, and members of charity organizations. Participants recorded a selfselected word that described their current mood when they were signaled. Joy and relaxation were reported 43% of the time, and sadness, anger, and fear were reported 22% of the time. On average, respondents reported positive emotions 68% of the time.
Diener, Larsen, and Emmons (1984) examined subjects' levels of mood in different situations. The moods ranged from slightly positive, when respondents were alone, to extremely positive, when participants were in social, recreational situations. Finally, Delespaul and deVries (1987) studied chronic mental patients living in the community and found that the average mood at the time these patients were signaled was above the neutral point of the scale.

These results of happiness were considerably higher than what laypeople and psychology professionals expected:

Diener et al. (2018) adds that:
Biswas-Diener, Vittersø, and Diener (2005) found that among the Inuit (indigenous people of Greenland), the Maasai (the traditional pastoralist-hunter tribe in southern Kenya and northern Tanzania), and the Amish, the vast majority of respondents scored above neutral in both satisfaction and affect balance. The self-report survey results were replicated with several other measures of SWB—informant reports, experience sampling, and a memory measure—reducing the plausibility that the positive responses are due only to self-report biases. In addition, all three groups were above neutral on satisfaction with each of 14 different life domains. Thus, the finding that most people are happy generalized to cultures that differ significantly from mainstream Western culture.
Diener, E., & Diener, C. (1996). Most People Are Happy. Psychological Science, 7(3), 181–185. https://doi.org/10.1111/j.1467-9280.1996.tb00354.x
Diener, E., Diener, C., Choi, H., & Oishi, S. (2018). Revisiting “Most People Are Happy”—And Discovering When They Are Not. Perspectives on Psychological Science, 13(2), 166–170. https://doi.org/10.1177/1745691618765111